![Why do ceramic underwear prices keep changing? | The parts and designs changed [OK Prostate Chip]](/img/a/T0316/eyecatch.svg)
This page is based on entries from "ok-lab's diary" (https://ok-lab.hatenablog.com/), the Japanese development diary written by Mr. Okada, founder of OK Lab, a small company in Japan (Okada Comfortable Life Laboratory). Only the entries about "tucking device and ceramic underwear prices and design changes" are summarized here, in order of publication. Past prices and sizes are as written at the time. Current prices come from the official product list (retrieved September 4, 2026). Quotations are translated from Japanese.
Note: This page is a personal reading log by someone with no connection to the maker or the seller. It reflects the source entries as of their publication dates and makes no guarantee of accuracy or safety. The product is not a medical device; talk to a doctor about any health decision. Check the official site for current information. This page contains advertising.
In short
Ceramic underwear prices changed as plates, belts, and fabric covers were redesigned.
Mr. Okada offered selected exchanges, changed supports, and withdrew some earlier configurations.
The current list prices the flat tucking set and its three separate parts.
About this product
The OK Prostate Chip is a small device that is placed in the urethra (the urine passage) so that it acts on the prostate; the maker sells it in several shapes, sizes and materials. It is made and sold by OK Lab (Okada Comfortable Life Laboratory), a small company in Japan, through its own online store, and prices are in Japanese yen (JPY). The maker's development diary, "ok-lab's diary", is written in Japanese. This page is an English summary of it, and every quotation is translated. OK Lab ships internationally, so readers outside Japan can order (see "Buying from outside Japan" below). Product names on this page are plain-English descriptions. The official Japanese product name is shown once in the product table so you can find the same item in the store.
Before you read: key terms
| Term | Plain-English meaning |
|---|---|
| Urethra | The urine passage; the chip acts on the prostate from within it. |
| Tucking device | An external plate-and-support arrangement intended to hold the penis in a concealed or compressed position. |
| Urethral rod, or bougie | An internal shaft used in earlier holding arrangements; the maker distinguished it from the external supports. |
| External support bar | A bar described as applying pressure from outside the body to help retain the tucked position. |
| Resin support bar | A rigid plastic support attached to the ceramic plate, intended to limit erections and support raised testicles. |
| Fabric tent | A raised stretch-fabric cover over the plate opening, intended to contain the penis tip and cover the testicles. |
| Testicle ring | An adjustable tubing loop intended to constrain the testicles; the diary later announced a temporary sales halt. |
| Retaining stops | Small barriers beside the plate opening, intended to keep fabric and straps attached. |
What happens: ceramic underwear prices
The OK Prostate Chip is a small device placed in the urethra (the urine passage) to act on the prostate. The related tucking devices have an external plate against the penis, held by belts or fabric. Later ceramic underwear adds a fabric tent (a raised stretch-fabric cover) over the plate opening. Mr. Okada describes this cover as containing the penis tip and surrounding testicles, while the entries document changes to parts and prices.
Tucking device prices covered individual parts and a complete set
The March 2023 announcement priced the flat tucking set at ¥15,000 (about $96 at ¥156 = $1, rate as of 2026-09-04) excluding tax, with the base plate, external support bar, and belt. The base plate alone cost ¥10,000 (about $64 at ¥156 = $1, rate as of 2026-09-04) excluding tax and measured about 9cm long, with a maximum width around 6cm. The separate belt was free-size and cost ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) excluding tax.
The external support bar cost ¥3,000 (about $19 at ¥156 = $1, rate as of 2026-09-04) excluding tax, with lengths of 11cm, 12cm, 13cm, and 14cm. Those same bar choices applied to the set. Mr. Okada invited requests for other bar lengths, with an additional charge depending on the requested size.
(Source: ok-lab's diary, published March 2023)
https://ok-lab.hatenablog.com/entry/2023/03/25/122614
Tucking device design changes widened the opening and prompted exchanges
In April 2023, the plate's central opening changed from approximately 7mm to approximately 20mm in diameter. Mr. Okada described a design with the urinary opening exposed on the plate's front. Development of the earlier condom-and-tube drainage arrangement stopped.
Existing purchasers could request a free exchange for the wider opening, although production would take time. Mr. Okada cautioned that exchanging plates would probably not help owners who had never achieved the intended tucked position. He invited exchange requests from owners who had achieved tucking and wanted the revised design.
(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/22/123057
Replacement tucking device plates omitted the earlier anti-slip tubing
In May 2023, Mr. Okada confirmed that replacement plates had been shipped. These omitted the 6mm tube previously attached to the plate. He wrote that the enlarged opening made the separate anti-slip barrier unnecessary.
Mr. Okada considered the simpler structure easier to clean. The diary does not record how recipients found these replacement plates in use.
(Source: ok-lab's diary, published May 2023)
https://ok-lab.hatenablog.com/entry/2023/05/13/123004
Mr. Okada abandoned full testicle concealment during tucking device development
A September 2023 entry described Mr. Okada's trials involving concealment of both the penis and testicles inside the body. He reported heart failure within hours during this testing. He writes that he then stopped attempting complete testicle concealment.
(Source: ok-lab's diary, published September 2023)
https://ok-lab.hatenablog.com/entry/2023/09/16/122723
January ceramic underwear prices separated the plate from its belt
The January 2024 announcement began sales of ceramic underwear and tube belts as separate products. The plate cost ¥7,000 (about $45 at ¥156 = $1, rate as of 2026-09-04) excluding tax, while standard belts cost ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) excluding tax. Belts outside the standard sizes carried an additional ¥1,000 (about $6 at ¥156 = $1, rate as of 2026-09-04) excluding tax.
The belt's stated purpose was to secure the ceramic plate. Mr. Okada explained that separate sales allowed purchasers to buy the plate without the company's belt.
(Source: ok-lab's diary, published January 2024)
https://ok-lab.hatenablog.com/entry/2024/01/13/123155
Ceramic underwear prices rose for the added resin support version
In February 2024, a version with a resin support bar (a rigid plastic support) and a glass clitoris-shaped decoration was announced. The earlier ceramic plate price was ¥7,000 (about $45 at ¥156 = $1, rate as of 2026-09-04) excluding tax; the version including the added resin component cost ¥11,000 (about $70 at ¥156 = $1, rate as of 2026-09-04) excluding tax. Its belt was priced separately at ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) excluding tax.
Mr. Okada described the revised product as closer to a restraint device than his original concealment concept. He attributed its erection-restraining action to the combined ceramic and resin structure.
(Source: ok-lab's diary, published February 2024)
https://ok-lab.hatenablog.com/entry/2024/02/03/123017
July ceramic underwear prices covered a belt, fabric cover, and plate
A July 2024 entry priced a tube belt at ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) excluding tax and a fabric tent at ¥4,000 (about $26 at ¥156 = $1, rate as of 2026-09-04) excluding tax. The ceramic plate was ¥6,000 (about $38 at ¥156 = $1, rate as of 2026-09-04) excluding tax, and the stated complete package price was ¥12,000 (about $77 at ¥156 = $1, rate as of 2026-09-04) excluding tax.
The belt returned from 4mm tubing to 6mm tubing, which Mr. Okada described as providing stronger tension. The three parts were supplied connected, with length adjustment limited to the belt ends. Mr. Okada accepted inquiries about custom sizes but cautioned that they would be considerably more expensive.
(Source: ok-lab's diary, published July 2024)
https://ok-lab.hatenablog.com/entry/2024/07/13/123018
Ceramic underwear design changes replaced tube belts with separate fabric briefs
A later July 2024 entry discontinued the tube-belt configuration in favor of a ceramic plate and separate string briefs. The briefs used swimsuit fabric for the cover, cords, and stitching. The plate cost ¥6,000 (about $38 at ¥156 = $1, rate as of 2026-09-04) excluding tax, and the free-size briefs also cost ¥6,000 (about $38 at ¥156 = $1, rate as of 2026-09-04) excluding tax.
The plate and briefs became detachable, and the fabric garment was described as machine-washable. A dedicated strap was added to concentrate pressure around the penis tip. Mr. Okada suggested that buyers could obtain spare briefs for laundry changes.
(Source: ok-lab's diary, published July 2024)
https://ok-lab.hatenablog.com/entry/2024/07/20/123059
The maker's answer to ceramic underwear prices
The maker changed the standard package, withdrew some constricting accessories, and added features addressing reported problems.
Standard tucking device sales excluded the internal urethral rod
The March 2023 launch excluded the urethral rod, or bougie (an internal holding shaft), from the standard range accompanying the flat tucking set. Mr. Okada said its safety considerations and handling difficulty differed substantially from the external components. He expressed concern about possible injury to the urine passage.
The standard offering therefore comprised the external plate, support bar, and belt. Mr. Okada said he would continue cautious development and publish further information if he found an approach he considered suitable.
(Source: ok-lab's diary, published March 2023)
https://ok-lab.hatenablog.com/entry/2023/03/25/122614
Ceramic underwear belt changes included a temporary halt to constricting accessories
A January 2024 announcement priced the belt with an added testicle-holding ring at ¥2,500 (about $16 at ¥156 = $1, rate as of 2026-09-04) excluding tax. The separate testicle ring (an adjustable tubing loop) used 6mm tubing measuring 25cm, and cost ¥500 (about $3 at ¥156 = $1, rate as of 2026-09-04) excluding tax. In February 2024, Mr. Okada announced a temporary sales halt for the constricting belt and testicle ring.
He also discussed the older arrangement for people specifically wanting that form of constriction. His preference was the newer arrangement without testicle tightening, which he considered gentler.
(Source: ok-lab's diary, published January 2024)
https://ok-lab.hatenablog.com/entry/2024/01/27/123012
(Source: ok-lab's diary, published February 2024)
https://ok-lab.hatenablog.com/entry/2024/02/03/123017
Ceramic underwear design changes addressed concentrated staining and loose fabric
In September 2024, Mr. Okada reported that sexual fluids, including prostate fluid, stained one spot because the plate kept the penis tip fixed. An absorbent pad was his proposed answer, but he found its adhesive reduced the fabric cover's stretch. He also reported that fabric and straps could detach during pad changes.
Retaining stops (small added barriers) were added beside the opening to address that detachment. Mr. Okada favored a pad arrangement that preserved the fabric's stretch.
(Source: ok-lab's diary, published September 2024)
https://ok-lab.hatenablog.com/entry/2024/09/14/123119
How ceramic underwear prices changed over time
| Published | What the diary said then |
|---|---|
| Nov 2018 | Restraint clothing prices: top ¥3,500, (about $22 at ¥156 = $1, rate as of 2026-09-04) middle ¥2,000, (about $13 at ¥156 = $1, rate as of 2026-09-04) bottom ¥2,500 (about $16 at ¥156 = $1, rate as of 2026-09-04); launch date undecided. |
| Mar 2023 | Sales would pause at production capacity and resume after outstanding manufacturing was completed. |
| Sep 2023 | The plate opening changed from an elongated oval to a diamond. |
| Sep 2023 | The stretch imitation-leather supplier was stopping production; equivalent replacement material was uncertain. |
| Sep 2023 | Black leather belts became standard, with less tubing around the penis-tip hook. |
| Jan 2024 | Tube belts used 4mm tubing with sealed ends and friction-based length adjustment. |
| Feb 2024 | Belts were simplified and supplied partly attached to the ceramic plate. |
| Jul 2024 | The early fabric-covered prototype had non-removable fabric and was unsuitable for machine washing. |
| Jul 2024 | Three fabric attachment slits received silicone reinforcement. |
| Sep 2024 | Future string-brief shipments would include a sample absorbent pad. |
OK Prostate Chip products related to ceramic underwear prices
The supplied current list prices the flat tucking set and its separate parts, but provides no size options.
Products that appear in these entries
| Product (official name) | Price incl. tax | Relation to this topic |
|---|---|---|
| Flat tucking base plate (エイン・デ・フラット用ベース板（単体）) | ¥11,000 (about $70 at ¥156 = $1, rate as of 2026-09-04) | The March 2023 launch priced this plate separately from its supports. |
| External support bar (エイン・デ・フラット用会陰棒（単体）) | ¥3,300 (about $21 at ¥156 = $1, rate as of 2026-09-04) | The March 2023 launch offered this support as a separately priced part. |
| Flat tucking belt (エイン・デ・フラット用ベルト（単体）) | ¥2,200 (about $14 at ¥156 = $1, rate as of 2026-09-04) | The March 2023 launch included a separate belt for the flat tucking device. |
| Flat tucking set (エイン・デ・フラット3点セット) | ¥16,500 (about $106 at ¥156 = $1, rate as of 2026-09-04) | The March 2023 announcement introduced the plate, support bar, and belt as a set. |
The flat tucking set is listed in OK Lab's own online store.
(Source: ok-lab's diary, published March 2023)
https://ok-lab.hatenablog.com/entry/2023/03/25/122614
Products the diary mentioned as alternatives
The diary names no alternative.
The entries also describe earlier restraint clothing, replacement plates, later ceramic underwear, and ceramic string briefs. No matching product can be confirmed on the current list.
Common worries about ceramic underwear prices
Reader questions concerned sitting discomfort, opening sizes, and the purpose of the extra resin support.
"Why did the tucking device hurt when sitting?"
In April 2023, a customer reported comfortable standing and walking but pain when sitting with the external support bar. Leaning forward and driving were also difficult, prompting a request for a solution. Staff thought the bar's length or curve could be leaving it too far from the body.
The diary does not record whether the discomfort was resolved. Staff proposed small curvature adjustments, followed by a different bar length if those changes did not help.
(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/22/123057
"Which ceramic underwear hole sizes were available?"
Answering a reader's sizing question in January 2024, Mr. Okada listed eight openings, each taller than it was wide. The vertical-horizontal dimensions were 26-24mm, 28-26mm, 30-28mm, 32-30mm, 34-32mm, 36-34mm, 40-34mm, and 45-34mm.
The diary does not record which size that reader chose. Mr. Okada said further large sizes could be considered if requested, while a completely custom handmade plate would cost about twice as much.
(Source: ok-lab's diary, published January 2024)
https://ok-lab.hatenablog.com/entry/2024/01/13/123155
"Did the ceramic underwear support bar make a difference?"
In March 2024, a customer asked whether adding the resin support changed the experience and which configuration to order. Mr. Okada said it helped restrain erections and support raised testicles. He did not describe the bar alone as sufficient to maintain that raised position.
The diary does not record the customer's eventual selection. Mr. Okada considered the resin bar optional when erection restraint was not a priority.
(Source: ok-lab's diary, published March 2024)
https://ok-lab.hatenablog.com/entry/2024/03/02/123027
Buying from outside Japan
OK Lab ships internationally to countries covered by Japan Post's EMS courier service. Overseas orders are paid in advance by PayPal. Each order carries a ¥400 (about $3 at ¥156 = $1, rate as of 2026-09-04) handling fee, and EMS shipping is charged on top. These terms come from OK Lab's official sales-terms page (written here as plain text, not a link: ok-lab.net/docs/law), checked on September 7, 2026; confirm them on the official store before you order, because they can change.
Summary of this article
| What you wanted to know | The answer |
|---|---|
| In short: why the changing prices? | Different announcements priced different parts and configurations. |
| About the product: who makes it? | OK Lab is a small company in Japan; prices are in Japanese yen. |
| Key terms: what are the separate components? | External plates, supports, belts, and fabric covers have distinct roles. |
| What happened to the designs? | Larger openings, added resin supports, and fabric briefs changed the configurations offered. |
| What did the maker change after problems? | He excluded internal rods from the standard set and revised accessories and attachment points. |
| What changed over time? | Materials, production arrangements, and fabric construction continued to evolve. |
| Which current products are listed? | The flat tucking set and its separate plate, support bar, and belt. |
| What did customers ask? | Questions concerned sitting pain, hole sizes, and the extra support bar. |
| How do overseas orders work? | Advance PayPal payment, an order handling fee, and additional EMS shipping apply. |
Source: ok-lab's diary (Okada Comfortable Life Laboratory). The original entries are in Japanese; quotations on this page are translated. Photos and videos are on the original entries.
This article is a summary of the maker's development diary. The product is not a medical device and no result is guaranteed. If anything feels wrong or worries you, see a doctor. Prices, specifications and cautions change, so confirm the latest information on the official blog and the official site. Questions about ordering and shipping go to the seller.