I'm selling this item because the size didn't fit. I only tried it on once after charging it. A simple black smart ring, USB rechargeable for convenience. - Color: Black - Accessories: USB cable, instruction manual Smart Ring Health Management [2024 New Release & 12 Days of Use] Compatible with Android/iPhone, Sleep Tracking, Smart Ring, Healthcare, 8 Exercise Modes, 3 Data Measurement Functions, IP68 Waterproof, USB Magnetic Charging, Camera Control, Small, Ultra-Lightweight, Calorie Counter, Exercise Distance, Pedometer, Activity Tracker, smart ring, Japanese Instruction Manual/Magnetic Charging Cable included Thank you for looking.