Each recharges in three hours using the included USB charging cord.
.After sliding your feet into the cozy fleece interior, the interior temperature can be set (by a button on each battery pack) to low, medium, or high to bathe the toes in luxurious warmth. Indoor/Outdoor Heated Slippers - Small - Black Sizes M (Women’s 6 1/2-8), L (Women’s 8 1/2-10); Men’s 7-8 1/2), and XL (Women’s 10 1/2-12; Men’s 9-10 1/2). The anti-slip soles assure a good grip indoors or out, and the waterproof 100% polyester exterior provides a barrier against the elements to keep feet dry.