Ultrahuman AIR Smart Ring 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!**

ALL-IN-ONE HEALTH INSIGHTS: This smart ring tracks 50+ health metrics, including heart rate, HRV, skin temperature, blood oxygen, stress, movement and recovery, with 20+ workout modes for activity. The all-new Emerald app unifies your data in one view. Built as a discreet health ring for proactive health and wellness, it turns daily patterns into clear, personalized next steps. Compatible with iOS and Android. DEEPER SLEEP, SMARTER RECOVERY: Use this sleep tracker to see REM, deep and light sleep, wakefulness, sleep debt and overnight temperature trends. Its heart rate monitor and HRV monitor feed your Sleep Index and Dynamic Recovery score, helping you understand when to push or recover. Worn as a comfortable sleep ring, it delivers actionable morning guidance, while Smart Alarm can wake you in a lighter sleep phase.