Product Description: Bluetooth:4.0 Battery:50mA Polymer Lithium-ion Charging Time:1 hour Waterproof:Life Waterproof Operating Temperature:-10 to 45 Storage Temperature:-20 to 60 Support:IOS 7.1 and Android 4.4 or above Synchronization Range: 3m(theoretical rang is 10m without any interference) Package Include: 1 x Smart Bracelet 1 x Manual Notes: 1. Please allow 1-3 cm difference due to manual measurement and 3-5 g for the difference between different colors. 2. Due to the screen difference, the color may be a little difference from what you expect, please allow it.