The Mayissi Black is a screenless health monitor you wear on your finger — a health monitoring ring for people who want their numbers without a watch on their wrist. Inside the band sits an optical sensor array, the small green and red LEDs that read pulse and blood oxygen through the skin, with motion and temperature sensing filling in the rest of the picture. The outside is a plain black band with a soft sheen, so it passes as ordinary jewellery in a meeting, on a video call or at dinner. As a smart ring sleep tracker it separates deep, light and REM sleep, marks the points where your night broke, and learns your own rhythm well enough to suggest a bedtime instead of quoting a generic eight hours. You get a short morning summary; the stage-by-stage detail is waiting when you want to dig in. Through the day it works as a smart health ring: steps, distance and calories, heart rate and blood oxygen readings, stress and recovery, plus skin temperature.
The health monitoring ring reads through the skin rather than from a cuff or a chest strap, sampling continuously through the day and night. What you see in the app is a trend line rather than a single snapshot taken when you remembered to check, and that difference is most of the value.
Five signals do the heavy lifting: heart rate, blood oxygen saturation (SpO2), skin temperature, heart rate variability (HRV) and stress. Each is useful on its own. Read together, they let the app build daily and weekly scores and flag shifts worth noticing — a resting heart rate that has crept up over a fortnight, a skin temperature running slightly above your own baseline, HRV falling while stress rises. The point of a smart health ring is that none of this needs managing: nothing to strap on, no readings to write down, and a plain-language summary at the end of it.
Cycle-aware tracking follows the same logic. Log your period in the app and the ring's temperature and HRV history turn it into a women's health tracker as well as a general one — reminders ahead of your cycle, and a view of how each phase lines up with your sleep and stress.
One honest boundary: this is a wellness device. It is built to show patterns and prompt better habits, not to diagnose or replace a clinical measurement.
The Mayissi Black is a consumer wellness product, not a medical device. It plays no part in diagnosing, treating or managing a diagnosed condition, and nothing it shows you should be read as a clinical result.
Where the numbers stop. Blood oxygen is an estimate of how your saturation is trending while you sit, sleep or train — it is not the pulse oximeter reading a clinician would act on. The ring has no ECG channel and no blood-pressure function, and it does not detect or treat sleep apnea; heavy snoring, waking unrefreshed or a suspected breathing pause at night belongs with a doctor, not an app. If you use the ring as a women's health tracker, treat cycle predictions as estimates built from the dates you log and your temperature history — they are not a contraceptive method.
Why a single reading can be off. Optical sensing needs steady skin contact, so a loose band, a cold hand, a change of sleeping position or a hard training session can each distort one sample. Treat a lone figure as a hint and give the seven-day or thirty-day line your attention instead — that baseline is what a health tracking ring is genuinely good at.
What it is good for. The slow shifts a fitness smart ring is made for: a resting heart rate that has drifted upward across three weeks, sleep debt building, or a stress score that climbs on the days you skip your evening walk. Use it to ask better questions of your own routine, and if something worries you, take the trend to your doctor as context — a conversation starter, not a diagnosis. When you feel unwell, reach for a clinical device or medical advice rather than the app.
| Water resistance | 5ATM — rated for daily wear, workouts and swimming |
| Swimming and sweat | Built to stay on in the pool, in the shower and through hard training sessions |
| Charging | Magnetic charging — the ring seats onto its charger and tops up without a cable plugged into the band |
| Charge time | About 1.5 hours from empty to a full charge |
| Battery life | 5 to 7 days of typical use per charge |
| Standby | Up to 15 days when the ring sits idle between charges |
| Connectivity | Bluetooth for the phone link and data syncing, plus GPS |
| Compatibility | iOS and Android, paired through the Mayissi app |
| Operating temperature | 0 °C to 50 °C |
| Updates | Firmware and app features arrive over the air, so improvements reach the ring without a computer |
At a desk. Meetings, video calls, a day of typing: the ring stays quiet. There is no screen to light up mid-presentation and no vibration on the wrist, which matters in rooms where a glance at your watch reads as disinterest. On a run. Multi-sport modes turn the ring into a fitness smart ring for the length of the session, recording duration, distance, pace, cadence and stride alongside heart rate. When the run ends, the same data sits next to the night's recovery figures instead of in a separate app. In the water. Pool sessions and showers do not require taking it off, so the ring stays on from the swim to the changing room to the commute. Travelling, and as a gift. Packed as a wearable smart ring, it takes less room than a watch and its charger. The remote shutter is genuinely useful on holiday, the ring finder earns its keep in hotel rooms, and a plain black band is an easy gift for someone who would never buy a smartwatch for themselves. - Nothing to subscribe to. Every tracking feature and the insight built on it comes with the ring. There is no monthly or annual plan to activate before the app becomes useful. - A full sensor stack in a band you can wear to bed. Optical heart rate and blood oxygen sensing, motion tracking and skin temperature share a housing thin enough to disappear on the hand. That packaging is why a health tracking ring can record continuously without becoming a wrist device. - Screenless by design. Nothing lights up, nothing buzzes. Your day is summarised in the app, not on your hand, which is the point for anyone who has ever silenced a smartwatch mid-meeting. - Built for water and sweat. Swimming, showering and hard training sessions are all part of normal use, so the ring does not have to come off between the gym and the office. - Extras with a purpose. Ring finder for the mornings it goes missing, a remote shutter for group photos, gesture control for the camera, and a couple of built-in games for the queue at the airport — a wearable smart ring that does more than log numbers. - Made for training as well as resting. Multi-sport modes record each session and line it up against the recovery data that follows, which is what makes this a fitness smart ring and not only a sleep device. - Updates after you buy. Over-the-air firmware keeps the ring improving rather than frozen at the software it shipped with.
Mayissi is the smart-ring brand of Tide Forge Tech, a health-monitoring technology company based in Shenzhen High-Tech Park (Nanshan), China, established in 2026. Our team of ten designs, develops and builds wearable health-tracking devices that are sold to customers worldwide. Because research, design and production sit under one roof, we can watch quality at every stage, from sensor performance to the finish you wear. Every customer receives clear setup guidance and responsive after-sales support, with our team reachable around the clock.
