Likely Compatible — verify the app

HPLSZCN Smart Ring + Ringlo: Know When It Is Actually Low

A plain gold band sold on Amazon, which we have not tested. What we can tell you is what we learned the hard way about these rings and their batteries.

What we know, and what we are guessing

Known: a plain gold band — not a gemstone ring, which is what this page used to say before we checked — with an Amazon product listing. No HPLSZCN ring has been tested here and we hold no data from one. The seller’s specifications are not repeated on this page because we cannot verify them.

The one question that decides it

Which app the listing names. SmartHealth or YCBT Life means the YCBT protocol and Ringlo reads it. Anything else and we cannot promise. If the ring is already on your finger, Ringlo’s scan settles it in a minute.

The battery, and a mistake we made for a hundred builds

These rings report their battery as a percentage and a status byte. We read that status byte backwards for about a hundred releases: the value that means “running low” we were reading as “charging”. So the app would show a charging bolt on a ring that was going flat, and it would stay quiet instead of warning. We found it by pulling 187,668 battery frames from 936 rings and checking what each value actually preceded. Forty-seven people had been shown the wrong thing about a dying ring.

It is fixed, and it is the kind of thing worth knowing about the category: a cheap ring’s own app is usually written by the people who wrote the firmware, and nobody outside checks their work. Ringlo now warns at a threshold you choose, again at 15%, and again at 5%, and stops warning while the ring is on the charger.

Why there is no photo on this page

The Amazon Associates terms do not permit us to store and serve the listing’s images, and we will not crop a screenshot of them. A Ringlo screenshot here would imply we had this ring paired, which we have not.

About the blood-pressure number

Almost every listing in this category advertises blood pressure. We took that apart on a ring we own, and the answer is the same for all of them: the figure is produced by the ring’s own firmware from your pulse, and it is an estimate, not a measurement. None of these rings has a cuff — we checked the capability flag on 941 of them and not one claims an inflatable band. The vendor’s own idea of “calibration” is a settings screen where you type in your normal blood pressure. Ringlo shows the number because your ring produces it, labels it an estimate, and never writes it to Apple Health or Health Connect, because a health record files it next to real cuff readings.

Why use Ringlo

The other rings we list

Every ring we list gets its own page saying what we have and have not tested on it: DL110 · COLMI R02 · Anarow · DREAM SPORT · Floral Enamel · CNBRO. The full list, with what each badge means, is on the compatible rings page.

Compare Ringlo with the stock app on the comparison page, or start on the Ringlo homepage.

Want to try the HPLSZCN with Ringlo?

Find the HPLSZCN on Amazon →

As an Amazon Associate, Ringlo may earn a small commission from qualifying purchases, at no extra cost to you. Each ring page says whether we've tested that ring.

Ringlo is an independent app and is not affiliated with, endorsed by, or sponsored by the makers of SmartHealth, HBand, Wearfit, or YCBT Life. Product names are trademarks of their respective owners.

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