What are penis rings and head covers for? | Their purposes and risks differ [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 rings and head covers" 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

The diary describes external accessories for covering the penis head, limiting movement, and managing urine leakage.

Mr. Okada changed materials and designs after discomfort, slipping, and urine splashing.

The current list includes the head-rim cushion, but several later accessories have no confirmed listing.

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 rings and head covers

The OK Prostate Chip is a small device placed in the urethra, intended to act on the prostate. These entries describe external accessories around the penis base, the head's rim, or the opening of a groin-worn plate. Mr. Okada proposed them for different purposes: limiting movement, covering exposed skin, or controlling leakage from an experimental urine-collection arrangement. His diary also records discomfort, slipping, and designs that failed during his own tests.

A head-rim cushion was proposed to limit chip movement

In an entry published in June 2019, Mr. Okada proposed a head-rim cushion (an adjustable ring) for limiting curved-chip movement. He discussed it as an alternative to a ring at the penis base, where pressure was intended to restrict movement. Mr. Okada warned that prolonged strong constriction there could cause tissue death.

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

An experimental penis ring followed Mr. Okada's report of discoloration

In an entry published in October 2022, Mr. Okada recalled accidentally leaving silicone rings on. He reported purple discoloration that he described as nearly reaching tissue death. His proposed alternative combined silicone with internal nylon, making a cord that he said barely stretched.

His experimental ring had a 20cm cord and loop fitting; the published October 2022 price was ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) tax excluded. He claimed the materials prevented tight knots and allowed easy release regardless of how the cord was tied. Mr. Okada proposed this alternative based on those claims; the diary does not record independent confirmation of its claimed safety.

(Source: ok-lab's diary, published October 2022)
https://ok-lab.hatenablog.com/entry/2022/10/01/122944

A penis head cover system needed gaps for urine flow

In an entry published in April 2023, Mr. Okada described a condom-and-tube system for the flat-plate assembly (a groin-worn device holding the penis inward). His aim was for urine to leave through tubing attached to the assembly.

The split-end drainage tube combined sections measuring 8mm outside/6mm inside and 6mm outside/4mm inside. He explained that the divided tip left gaps through which urine could reach the tube despite pressure against the head.

With a stopper, this tube cost ¥500 (about $3 at ¥156 = $1, rate as of 2026-09-04) tax excluded, as published in April 2023. Mr. Okada cautioned that without the divided section, pressure could prevent urine from entering the tube.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/08/122508

Heat-sealed penis head covers replaced stitching after Mr. Okada reported discomfort

In an entry published in May 2023, Mr. Okada introduced a heat-sealed head cover (stretch fabric joined using heat instead of sewing thread). He intended it to cover the exposed head emerging through a flat plate. He had worried that sewing thread might injure sensitive tissue.

After testing a stitched version, he reported discomfort where thread was compressed against the head's rim. He said the heat-sealed version eliminated that irritation in his own test. Mr. Okada also warned that the tight plate could not be pulled off by force.

(Source: ok-lab's diary, published May 2023)
https://ok-lab.hatenablog.com/entry/2023/05/13/123004

Mr. Okada found ceramic plates needed a less slippery head cover

In a separate entry published in May 2023, Mr. Okada reported slipping after changing the plate material from resin to ceramic. He found that the head could slip back when only its tip extended through the smooth ceramic opening.

His proposed cover added fabric between that surface and the skin, which he said increased friction. Mr. Okada identified the heat-sealed head cover as his proposed answer to this specific slipping problem.

(Source: ok-lab's diary, published May 2023)
https://ok-lab.hatenablog.com/entry/2023/05/20/123034

A wire head cover was abandoned after it scattered urine

In an entry published in June 2023, Mr. Okada abandoned his wire-net head cover after finding that it could split and scatter urine. This happened when the net touched the urine outlet. He replaced the mesh with a ring-shaped cover, leaving an open center.

He then added a less favorable result from an overnight test involving a bougie (an instrument whose purpose these entries do not explain). He reported that movement of the instrument also moved the cover. Mr. Okada warned that the replacement ring might not function effectively alongside that instrument.

(Source: ok-lab's diary, published June 2023)
https://ok-lab.hatenablog.com/entry/2023/06/17/123116

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The maker's answer to penis rings and head covers

Mr. Okada's proposed measures addressed leakage and fit, with different rings serving different positions.

Bead-adjusted penis rings targeted backflow when a condom became swollen

In an entry published in April 2023, Mr. Okada described bead-adjusted rings (doubled silicone loops sized with a sliding bead). The material was silicone tubing with an outside diameter of 1mm. He assigned one ring to the penis head's rim, over a condom, with the aim of preventing urine backflow.

He reported that an overly loose ring could allow the condom to inflate when incoming urine exceeded the tube's capacity. He associated that swelling with urine flowing backward. Mr. Okada cautioned that ring fit mattered for preventing leakage.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/08/122508

The second penis ring sealed a different potential leak

The second bead-adjusted penis ring described in April 2023 was intended to stop leakage at the tube's connection outside the plate. Mr. Okada distinguished the reinforced overlap between tube sections from the softer section without that overlap. The rings cost ¥500 (about $3 at ¥156 = $1, rate as of 2026-09-04) tax excluded for a set of 2, as published in April 2023.

He offered replacement parts and separately quoted larger or longer custom versions. Mr. Okada warned that excessive pressure could dent tubing where the sections did not overlap.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/08/122508

An adjustable penis ribbon addressed poor fit with fixed rings

In an entry published in January 2024, Mr. Okada introduced an adjustable penis ribbon (a silicone-tube ring with a sliding stopper). The described ring used 2.5mm tubing, 15cm long, and cost ¥500 (about $3 at ¥156 = $1, rate as of 2026-09-04) tax excluded as published that month. It was intended mainly for the head's rim, although he said its size adjustment allowed other positions.

He reported that the silicone helped reduce slipping at the contact between the head's rim and ceramic underwear. Mr. Okada proposed this adjustable ring for situations where fixed-size silicone rings did not fit well.

(Source: ok-lab's diary, published January 2024)
https://ok-lab.hatenablog.com/entry/2024/01/27/123012

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 rings and head covers changed over time

The diary does not say what the current state is.

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OK Prostate Chip products related to penis rings and head covers

The current list includes the three-piece flat-plate assembly and head-rim cushion discussed in these entries.

Products that appear in these entries

The three-piece flat-plate assembly is listed in OK Lab's own online store.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/08/122508

Products the diary mentioned as alternatives

The head-rim cushion is listed in OK Lab's own online store.

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

Silicone-and-nylon ring, bead-adjusted rings, split-end drainage tube, and heat-sealed head cover: No matching product can be confirmed on the current list. Replacement cover ring, wire head protector, and adjustable penis ribbon: No matching product can be confirmed on the current list.

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Common worries about penis rings and head covers

The recorded customer concerns involve grip, uneven plate contact, and uncomfortable shaft bending.

"Why do penis accessories fail to grip behind the head?"

An entry published in April 2023 mentions customer reports that stocking-based accessories could not catch behind the penis head. Mr. Okada described these reports as involving people without a pronounced groove behind the rim. He connected that issue to the possibility that his bead-adjusted ring might also shift. Mr. Okada cautioned that this ring could slip when that groove was absent.

(Source: ok-lab's diary, published April 2023)
https://ok-lab.hatenablog.com/entry/2023/04/08/122508

"Why won't my penis accessories sit evenly against the body?"

In an entry published in June 2023, a customer said the upper part of a wide-opening plate did not sit against their body. The lower part felt secure, and they wanted to understand the uneven fit. Mr. Okada attributed the upper gap to the angle of the supporting rod.

The diary does not record whether the fit improved after his reply. Mr. Okada's answer emphasized a balance between the support angle and belt pressure.

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

"Can penis accessories prevent shaft bending when held inward?"

The same customer, in the entry published in June 2023, also asked about shaft bending when the penis was held inward. They reported severe pain during an attempt involving a steel bougie. Mr. Okada said differences in the urine passage's length and stiffness made dependable advice difficult.

He nevertheless suggested partial inward positioning, and described the new net as a possible answer to protrusion through larger plate openings. The diary does not record whether these proposals helped this customer. Mr. Okada asked for other customers' experiences because he could not provide a reliable general answer.

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

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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.