Wellue Checkme O2 Max Wrist Overnight Pulse Oximeter

The Wellue Checkme O2 Max is a wrist-worn overnight pulse oximeter. A soft ring sensor on your finger records blood oxygen (SpO2) and pulse rate, while the battery, display and electronics sit on a wristband. The battery runs up to 72 hours between charges, so you can record several nights in a row and see how your oxygen levels behave while you sleep on CPAP.

Key Features

• Wrist unit, light finger sensor — only the soft ring sensor sits on your finger; the weight of the battery and electronics rests on your wrist.
• Up to 72 hours of battery — several nights between charges, rather than a recharge every morning (manufacturer figure for typical use).
• Continuous overnight recording — SpO2 and pulse rate are sampled every second for the whole night, not just spot-checked.
• Silent vibration alert — the wrist unit vibrates when oxygen falls below, or pulse moves outside, a threshold you set in the app. It can be switched off.
• Four nights stored on the device — up to 10 hours per session, synced to your phone over Bluetooth when it suits you.
• Shareable reports — the app and PC/Mac software produce printable PDF and CSV reports you can take to your GP or sleep specialist.
• On-wrist display — check your current reading at a glance without reaching for your phone.

Checkme O2 Max, O2Ring or O2Ring-S?

CPAP Club stocks all three, and they measure the same things: blood oxygen and pulse rate through the night. The differences are where the device sits and how often you charge it.

Choose the Checkme O2 Max if a ring-mounted device feels heavy or bulky on your finger, if you tend to knock it against the pillow, or if you want the fewest charges. Choose the O2Ring-S if you would rather have a single piece with nothing on your wrist and no cable, but still want a few nights between charges. The original O2Ring does the same job with a daily charge.

What the 72-Hour Battery Means

The 72 hours is battery life, not the length of a single recording. Each session records up to 10 hours, and the device holds four sessions before it needs to sync. In practice, that means you can wear it for a few nights, sync to the app, and only then think about charging. A full charge takes around two to two and a half hours.

Using It Alongside CPAP Therapy

A CPAP machine reports how many breathing events it detected. An oximeter shows something the machine cannot: what your blood oxygen actually did through the night. Seeing both side by side gives you, and whoever is looking after your therapy, a fuller picture.

When you open a report, the two numbers to understand are:

• SpO2 — the percentage of your blood's oxygen-carrying capacity in use. Healthy adults typically sit around 95–100% while awake, and small dips during sleep are normal.
• Pulse rate — your heart rate in beats per minute, which often rises briefly when breathing is disrupted.

Overnight oximetry reports generally summarise your lowest and average oxygen, the time spent below 90%, and how often oxygen dropped by a set amount. If you notice repeated drops or long periods below 90% while using CPAP, take the report to your GP or sleep specialist rather than adjusting your pressure yourself. An oximeter records oxygen; it cannot tell you why it dropped — a mask leak, a pressure setting or something unrelated to sleep apnea can all look similar on the trace.

Who Is This For?

It suits CPAP users who want to check how their oxygen levels hold up on therapy, particularly in the first months or after a mask or pressure change. It also suits anyone who has found a finger-mounted ring uncomfortable, and partners or carers who want a simple record to bring to the next appointment.

It is not a substitute for a sleep study. If you think you may have sleep apnea but have not been diagnosed, speak to your GP first. And if you already own an O2Ring that you find comfortable and charging it is not a nuisance, there is no need to switch. For a quick daytime reading, a simple fingertip pulse oximeter does the job for less.

What's in the Box

• Checkme O2 Max wrist unit with wristband
• Finger ring sensor with cable
• USB charging and data cable
• User guide

Frequently Asked Questions

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