It can be heated directly by the charger.This electric heating shoe can heat up for a long time.A good gift to parents, children, lover and friends.Power saving, safety, winter must. This shoe is a size fits all for women and fits sizes 35-39.Soft , comfortable to wear. It also can be used as home shoes.Colour:PinkMaterial:super soft velvetPackage Contents:1 pair * USB Charging Warmer Foot ShoesOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.