Is a Larger Penis Plate Hole Better? | Easier Positioning, With Risks [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 "penis plate hole size" 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.

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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 wider opening exposed the urinary opening, but one smaller-hole prototype proved difficult for the maker to remove.

Mr. Okada favored the redesign for positioning and drainage, while acknowledging breakage and clothing friction.

The current list includes a separate base plate but does not confirm which historical hole sizes remain available.

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.

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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.

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Before you read: key terms

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What happens: penis plate hole size

The OK Prostate Chip is a device placed in the urethra (the urine passage), where the maker describes it reaching the prostate. Here, the related product is an external plate intended to hold the penis concealed against the body. Its opening surrounds the glans (the head of the penis), near the urinary opening. The entries follow changes to that opening's size, its ability to hold position, and the way urine leaves the plate.

A wide-hole plate exposed the urinary opening instead of covering it

In an entry published in April 2023, Mr. Okada described enlarging the central hole from about 7mm to about 20mm. The older plate covered the glans, leaving small openings for instruments and urine. The redesign exposed the area around the urinary opening on the plate's outer face.

Mr. Okada said the new opening held the glans without relying on a urethral sound (a rod-like urethral instrument). He reported that even 1mm of movement had disappeared in his own test. He favored the wide-hole version because he considered this positioning more reliable.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/22/123057

One wide-hole plate prototype proved difficult for Mr. Okada to remove

In an entry published in May 2023, Mr. Okada compared prototype openings around 2.5cm and 2cm across. He reported easier passage and return with the larger opening, despite the exposed glans measuring about 3.5cm. His account described no problem during prolonged exposure, but did not include a fully rigid erection.

With the smaller opening, he reported that the glans passed through but did not readily return. The plate remained attached even after the belt was removed. Mr. Okada advised against complete passage for anyone whose erection might prevent removal.

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

Larger wide-hole plate sizes delayed the planned ceramic launch

In an entry published in June 2023, Mr. Okada reported receiving ceramic plates beyond the earlier 20mm-15mm opening. The newly delivered hole sizes were 22-20, 24-22, 26-24, and 28-26. However, further development had already prompted requests for 30-28 and 32-30 openings.

Sales were to begin only after those larger plates arrived. Mr. Okada expected some smaller-hole stock to remain unused and planned increased production of larger sizes. The diary does not record a completed launch in that entry.

(Source: ok-lab's diary, published June 2023)
https://ok-lab.hatenablog.com/entry/2023/06/10/123053

The largest wide-hole plate still left the best size unsettled

In an entry published in July 2023, Mr. Okada reported that the largest delivered ceramic opening measured 32-30mm. Its rim had been narrowed as far as he believed its strength allowed. He intended that size for customers with larger penises, yet found it the easiest delivered plate to wear himself.

He said it did not feel too large and requested 34-32 and 36-34 versions. Those additional plates were expected near the end of the following month. Mr. Okada withheld a best-size judgment until he could test the larger versions.

(Source: ok-lab's diary, published July 2023)
https://ok-lab.hatenablog.com/entry/2023/07/01/123130

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The maker's answer to penis plate hole size

Mr. Okada changed the opening, preferred connection, and supporting structure as his trials revealed different needs.

The wide-hole plate changed drainage and ended an earlier collection project

In an entry published in April 2023, Mr. Okada described urine emerging from behind the old plate and soiling its inner face. With the redesign, he reported urine leaving from the front and no longer soiling the back. He said a bidet (a washing spray) could then reach the exposed surfaces directly.

He stopped developing the earlier condom-and-tube urine-collection arrangement after adopting the exposed-opening design. He no longer wanted a collection covering to hide the exposed part of the glans. Mr. Okada favored the new arrangement despite acknowledging some inconvenience with urination and washing.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/22/123057

A wide-hole plate led Mr. Okada to favor flexible connections

An entry published in April 2023 also changed the maker's preferred connection for devices associated with the concealing plate. Mr. Okada had previously favored a flat urethral sound, but now described that relatively rigid form as difficult in the concealed arrangement. He attributed the difficulty to twisting and compression of the urethra.

He instead favored a two-wire jointed connection (a bendable link between device parts). His reasoning emphasized its flexibility compared with the flat sound. Mr. Okada named the two-wire jointed connection as his first choice for this changed arrangement.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/22/123057

The wide-hole plate simplified positioning in the maker's explanation

In an entry published in May 2023, a reader asked how the penis could fit beneath the plate. Earlier descriptions and illustrations had not made the arrangement clear to them. Mr. Okada explained that part of the shaft remained near the body's surface, beneath the external plate.

He said the enlarged opening held the glans's position, removing a positioning difficulty associated with the older covered-head design. The diary does not record whether that reader subsequently achieved a comfortable fit. Mr. Okada strongly favored the wide-hole version because he considered this more stable positioning easier to manage.

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

A lighter wide-hole plate design dropped the separate support rod

In an entry published in July 2023, Mr. Okada defined a lighter belt-only ceramic plate (X Plate). The earlier assembly combined a perforated ceramic plate, an aluminum perineal rod (a support bar), and a belt. The new design omitted the rod and used imitation-leather belts, with a revised lower fastening intended to provide some support.

The belt sections likely to get wet were tubing. Mr. Okada reported a continuous downward urine stream while seated, with direction controllable through the plate's edge near the pubic bone. He presented the belt-only construction as a lighter, simpler option for holding the plate at the groin.

(Source: ok-lab's diary, published July 2023)
https://ok-lab.hatenablog.com/entry/2023/07/29/123449

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.

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How penis plate hole size changed over time

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OK Prostate Chip products related to penis plate hole size

The current list includes a separate base plate but does not specify its hole sizes.

Products that appear in these entries

The separate base plate is listed in OK Lab's own online store.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/29/123107

Products the diary mentioned as alternatives

The diary names no alternative.

Two-wire jointed assemblies and the belt-only ceramic plate (X Plate): No matching product can be confirmed on the current list.

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Common worries about penis plate hole size

Readers asked about replacement arrangements, fractures, and whether the enlarged opening could allow slipping or clothing contact.

"Did the wide-hole plate exchange require returning the original?"

In an entry published in April 2023, Mr. Okada offered existing owners a replacement free of charge, following an email request. He planned the wide-hole specification for all future plate releases, but replacements would take time and would not be sent automatically. He cautioned that replacement might not help someone who could not achieve concealment with the original.

In another entry published in April 2023, a customer asked whether only the base plate needed returning. The published policy required no return, allowing owners to keep both versions; the diary does not record this customer's later experience. Mr. Okada encouraged owners satisfied with the earlier version to request a replacement as well.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/22/123057

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/29/123107

"Could enlarging a wide-hole plate cause it to break?"

In an entry published in April 2023, a customer reported that their newly received plate broke while worn after they enlarged its opening. They then asked to order a maker-supplied wide-hole version. Mr. Okada replied that his own first enlarged-hole prototype had not broken.

He suspected that the remaining small holes might have left an unfavorable balance around the customer's altered opening. His reply did not establish the cause of that fracture. The diary does not record whether the customer's requested replacement order was completed.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/29/123107

"Would a wide-hole plate prevent slipping, rubbing, or breakage?"

In an entry published in April 2023, a customer asked about pain, outward slipping, underwear contact, and plate strength. Mr. Okada said blood-filled swelling and slippery pre-ejaculate (fluid associated with arousal) could let the glans gradually slide outward. He acknowledged underwear friction when the glans protruded and said pain varied between individuals.

Staff offered a wide-hole replacement, but the diary does not record this customer's experience with it. Mr. Okada considered the original small-hole layout more vulnerable where little material remained between neighboring openings. He warned that epoxy (the plate's resin material) could break under strong force, although the wider version had no extremely narrow sections.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/29/123107

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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.

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Summary of this article

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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.