1：Battery not included

2：We are Asian size, 2-3 sizes smaller than European size, please choose the right size according to our size chart。

3：Recommend  batteries model, please use batteries with high USB Power Delivery（unit：W）， The higher the USB Power Delivery, the higher the heating temperature.（output Power (W)=Voltage (V) × Current (A).）

for example ：output power 10W=5V*2A   / output power 22.5W=5V*4.5A