What is a curved prostate chip? | A rear curve, with comfort and removal concerns [OK Prostate Chip]

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 "curved prostate chips (fetal chips)" 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

• A curved tail was intended to steady the chip, but discomfort and removal difficulties were reported.
• Mr. Okada changed the tail shape and warned about tight compression, motor compatibility, and long rigid designs.
• The September 2026 product list includes ceramic curved-tail chips and the plain motor-only model.

If you see blood in your urine, even a small amount or for the first time, do not wait and see. See a urologist right away.

If you suddenly cannot urinate, or the device cannot be removed, do not try to fix it yourself. Go to a medical facility, including emergency care, immediately.

---

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

---

What happens: curved prostate chips

The OK Prostate Chip is a small device placed in the urethra (the urine passage) to act on the prostate. Its curved tail extends from the rear and was intended to steady the chip's position near the prostate. Mr. Okada also developed a tiny motor-only model, nicknamed the fetal chip, intended to provide vibration. These entries cover both the tail shape and the small vibrating model.

Curved prostate chips began with a cable-strength problem in March 2019

In an entry published in March 2019, Mr. Okada reported cable failures during repeated bending tests. The vinyl-covered wire measured 1 mm across and contained 6 strands; he attributed the failures to metal fatigue (damage from repeated bending). Version 2 adopted silicone-covered wire measuring 1.2 mm, with 24 strands.

Moving the connection to the chip's rear reduced motor-section thickness by more than 1 mm. Reinforcing the next 8–10 mm with resin (the coating around the joint) produced the curved tail. Mr. Okada presented the curve as his solution to the extra length created by reinforcing that connection.

(Source: ok-lab's diary, published March 2019)
https://ok-lab.hatenablog.com/entry/2019/03/23/173222

Curved prostate chips also developed into prototypes without motors

In another entry published in March 2019, Mr. Okada extended the curved-tail idea to chips without motors. He discussed resin, glass, and ceramic prototypes, with a decorative hole possible in some designs.

Proposed prices, excluding tax, were ¥4,000 (about $26 at ¥156 = $1, rate as of 2026-09-04) for a resin short and ¥5,000 (about $32 at ¥156 = $1, rate as of 2026-09-04) for glass or ceramic shorts. Glass or ceramic medium-length versions were ¥6,000 (about $38 at ¥156 = $1, rate as of 2026-09-04); other versions were the existing chip price plus ¥2,000, (about $13 at ¥156 = $1, rate as of 2026-09-04) excluding tax. Mr. Okada proposed ceramic as another material because making the hole was easier.

(Source: ok-lab's diary, published March 2019)
https://ok-lab.hatenablog.com/entry/2019/03/30/160657

Curved prostate chips gained rounded ends after a discomfort report

In an entry published in July 2019, a customer reported on a free rubber coating added after complaints about a pointed tail. After about two uses, the mild prickling pain had gone, but the sensation of something poking into the urethra remained. The customer preferred a rounded end.

Mr. Okada acknowledged that a pointed end served no function and changed production to rounded ends starting the day before publication. His response favored changing the shape instead of preserving a point simply to resemble a curved bead.

(Source: ok-lab's diary, published July 2019)
https://ok-lab.hatenablog.com/entry/2019/07/27/130537

The tiny fetal chip had a separate planned package price

In an entry published in August 2019, a customer asked to buy a tiny vibrating chip shown in an earlier entry. Mr. Okada replied that development was continuing and sales were expected soon. The proposed motor-only model measured about 20 mm long, up to 5 mm thick, and 9 mm wide at one point.

The planned package contained the chip and dedicated battery box for ¥3,000 (about $19 at ¥156 = $1, rate as of 2026-09-04) excluding tax, without a battery. The diary does not record whether this customer's purchase was completed. Mr. Okada cautioned that the small body could be difficult to feel without vibration.

(Source: ok-lab's diary, published August 2019)
https://ok-lab.hatenablog.com/entry/2019/08/24/125858

The plain fetal chip allowed a different motor by request

In an entry published in December 2019, a customer requested the plain motor-only chip with a 10 mm motor. The listed historical price was ¥3,300 (about $21 at ¥156 = $1, rate as of 2026-09-04), and the customer wanted a connector instead of buying a controller.

Mr. Okada explained that the store's 8 mm listing could be changed to 10 mm by request. The diary does not record how this customer's chip felt in use. His ordering advice was to specify the different motor size in the order message.

(Source: ok-lab's diary, published December 2019)
https://ok-lab.hatenablog.com/entry/2019/12/28/131319

Curved prostate chips gained a distinct motor-backed description in January 2022

In an entry published in January 2022, Mr. Okada described attaching a motor behind an intact chip. Earlier vibrating designs replaced the chip's rear bulge with a motor instead.

He named the new arrangement a curved-tail vibrating type, priced at the ordinary chip price plus ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) excluding tax. The nonmotor curved-tail addition cost ¥1,000 (about $6 at ¥156 = $1, rate as of 2026-09-04) excluding tax above the ordinary chip price. Mr. Okada's pricing explanation specified that controller costs were separate.

(Source: ok-lab's diary, published January 2022)
https://ok-lab.hatenablog.com/entry/2022/01/29/123455

---

The maker's answer to curved prostate chips

The diary's responses address the tail shape, pressure-related risks, motor compatibility, and the difficulty of removing long rigid designs.

Holding curved prostate chips firmly prompted a warning about tissue damage

In an entry published in June 2019, Mr. Okada discussed pressure rings intended to reduce chip movement. He warned that prolonged tight compression could cause necrosis (tissue death), mentioning about 30 minutes in that warning. His caution was against prolonged or excessive tightness.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/01/155432

A separate Bluetooth controller inquiry addressed motor compatibility

In an entry published in January 2022, a customer asked whether a Bluetooth controller (a unit controlling the chip's motor) could be sold separately. Mr. Okada first asked for time to reconsider, then announced separate controller sales as the standard arrangement.

He also reported that the selected controller operated only 8 mm motors; 10 mm motors did not run. He reported damage to 6 mm motors on connection, and said he did not know why. Mr. Okada explicitly warned about that damaging combination.

(Source: ok-lab's diary, published January 2022)
https://ok-lab.hatenablog.com/entry/2022/01/22/123342

Long rigid curved prostate chips prompted a difficult-removal warning in May 2023

In an entry published in May 2023, a customer reported being unable to remove a large, strongly curved chip after half a day. The customer asked how to prevent a repeat after it came out during urination the next morning. Staff said the strongly curved body and added tail were each designed to resist slipping out, making their combination especially difficult to remove.

Staff's qualified safety claim depended on the tail remaining in the bulbar urethra (the section intended to accommodate it). Mr. Okada suspected a tail displaced into the prostate area could return at the wrong angle, explaining why pulling alone might fail. He warned against deeply positioning long rigid chips where their original angle could not be maintained on the way out.

(Source: ok-lab's diary, published May 2023)
https://ok-lab.hatenablog.com/entry/2023/05/06/123024

If you see blood in your urine, even a small amount or for the first time, do not wait and see. See a urologist right away.

If you suddenly cannot urinate, or the device cannot be removed, do not try to fix it yourself. Go to a medical facility, including emergency care, immediately.

---

How curved prostate chips changed over time

The diary does not say what the current state is.

(Source: ok-lab's diary, published March 2020)
https://ok-lab.hatenablog.com/entry/2020/03/14/141804

---

OK Prostate Chip products related to curved prostate chips

The current list includes ceramic curved-tail models and the plain motor-only chip; historical custom specifications are separate.

Products that appear in these entries

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/01/155432

(Source: ok-lab's diary, published December 2019)
https://ok-lab.hatenablog.com/entry/2019/12/28/131319

(Source: ok-lab's diary, published August 2025)
https://ok-lab.hatenablog.com/entry/2025/08/23/122935

Products the diary mentioned as alternatives

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/01/155432

The March 2019 prototypes, November 2021 build, November 2022 combinations and slim model, and August 2025 assembly are historical designs. No matching product can be confirmed on the current list.

---

Common worries about curved prostate chips

The replies distinguish motor size, overall length, and custom shape; they do not record successful use for every request.

"Could the fetal chip fit when another vibrating model did not?"

In a separate case published in August 2019, a customer still could not accommodate a vibrating chip after its body had been made thinner. The customer wanted news of a smaller motor design.

Mr. Okada believed the tiny motor-only model's short, rounded, sharply tapering body could address this customer's difficulty. He noted that the customer could already accommodate a medium-length chip. The diary does not record a later trial of the proposed alternative. Mr. Okada qualified his suggestion because he did not know whether that model would meet the customer's intended purpose.

(Source: ok-lab's diary, published August 2019)
https://ok-lab.hatenablog.com/entry/2019/08/24/125858

"Are longer curved prostate chips the answer for beginners?"

In an entry published in November 2022, a reader proposed a longer, thinner chip with little curvature for beginners reporting difficulty reaching the intended position. Mr. Okada replied that a curved tail could extend a ceramic chip by about 15 mm, making a short version about 45 mm.

He also mentioned a short chip with a flat add-on and a slim curved model as possibilities. His reply treated curvature or flexibility as important, rather than treating length alone as the answer. He described these judgments as based on his experience and said the proposal had been passed to the blue-chip maker. Mr. Okada advised against chips over 40 mm for beginners already struggling to reach the intended position.

(Source: ok-lab's diary, published November 2022)
https://ok-lab.hatenablog.com/entry/2022/11/12/122932

"Can curved prostate chips be made from twisted ceramic models?"

In an entry published in September 2023, a customer requested a curved-tail version of the long ceramic twist chip. Staff initially explained that their usual process suited flat chips and warned that the twisted version might come out distorted.

They nevertheless offered the work for an additional ¥1,100 (about $7 at ¥156 = $1, rate as of 2026-09-04), and the customer accepted. Mr. Okada then reported making the piece and finding its proportions attractive; the diary does not record how it felt in use. Staff's advice before acceptance was to consider the possible distortion.

(Source: ok-lab's diary, published September 2023)
https://ok-lab.hatenablog.com/entry/2023/09/09/122848

---

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

---

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.