Hi, This is Johnny, From Shenzhen Grepow Battery Co., LtdGrepow is one of the world's largest battery manufacturer. We are the world leading battery manufacturer specialize in special shaped batteries, high discharge rate battery and modular battery in China, and among the top 5 Ni-MH manufacturers in the world, also manufacturing the LiPo and LiFePO4 battery. We are an advanced company offering research, development, production, and sales services.Shaped battery, customizable size and shape-50℃ ultra-low temperature lithium battery50C high discharge rate batteryNMC 811 high energy density battery (≥275Wh/kg)5C fast charge batterySelf-developed patented steel shell button-cell battery (rechargeable lithium battery)Any shapes battery customization.Smart Ring battery ------ Ring sizeRound battery --------- Smart Watch 、 Tracker 、DiveGRP1254 ------------ TWS headsatlijunlin@grepow.com