Tulbeys Fitness Tracker Smart Ring US size 7 Silver stainless steel Swing hand and take a photo! Waterproof 2 hour charging time 5-7 day battery life 2.8mm thickness Lightweight and comfortable APP data real time Variety of sports modes Blood oxygen monitoring Step, sleep & heart rate tracking Compatible with smartphones Includes smart ring, box, user manual, & charging cable This is a great smart ring with a cool feature to take a picture by swinging your hand! I bought to try it out but decided to stay with my smart watch. Only wore it for 1 day, so in excellent like new condition!