Pros:heart rate is measured is accurate, checked with treadmill too. But u have to adjust the position on the wrist to be preciseBattery life is really good, it’s been 3 days and it has reduced from 99-93. So I think it might come close to 40 daysBand is light weight and seems to take showering wellCons:When u sweat a lot the heart rate measurement is a bit offSleep data is good but it only tracks main sleep, and naps are not shown on the appConclusion: for the price it’s a good band that does everything it claims to about 80% accuracy.Update after using for 2 weeks. Sleep data is so wrong. It won’t measure and gaps are recorded regularly. Heart rate shown is always 20-30 bpm less. And if position or tightness or sweat then u cannot rely on heard rate. Steps are recorded even when ur sleeping lol. Bottom line : don’t rely on this band it’s totally waste of money. Instead save up and buy a whoop.Final update: we need to wear it 1 inch outside of the wrist bone for accurate measurements. After I figured this out my tests have been delightful. Solid battery life (atleast 35 days), water resistant, heart rate, sleep (except naps), blood oxygen, HRV measurements for a fraction of cost. The app still needs some work though, it’s a Chinese app and could have been better but for the strap itself I will give 5 stars. I wish they sold other colours strap separately.