Unisex Smart Bracelet Wristband Watch Blood Pressure Oxygen Heart Rate Fitness Tracker Friendly Tips: 1. Please kindly allow 2-3% difference according to manual measurement. 2. Please check the measurement chart carefully before you buy the item (inch = 2.54 cm). 3. Please note that slight color difference should be acceptable due to the light and screen. Thanks. Specification: Battery capacity: 100mAh Battery type: lithium polymer battery Display: 0.96 HD color screen APP: YOHO Package Contents: 1 x Smart Bracelet Promise If the product has any quality problems, please feel free to contact us, we will help you solve the problem as quickly as possible.