ULTRAHUMAN Ring AIR Matte Grey sells on Amazon. I think the price is very good. Please read some of the reviews and see people thought of the product.**If you’re not sure whether to buy, add to cart, and you can come back to it later!**

YOUR ALL-IN-ONE SMART RING  100+ HEALTH METRICS, NO APP FEE: Monitor heart rate, HRV, blood oxygen (SpO2), skin temperature, stress, and recovery from a single 2.4g titanium ring  the lightest smart ring available. Every core feature is free in the Ultrahuman app. No hidden fees. Compatible with iOS and Android.

ADVANCED SLEEP & RECOVERY TRACKER: Detailed insights into every sleep stage  REM, Deep, Light, Wakefulness. Track accumulated sleep debt and skin temperature trends. Smart Alarm wakes you at your lightest phase. Daily recovery score with actionable nudges. Clinically validated sensors.