ororo Wireless Cut-To-Fit Heated Insoles with Charger& Remote Control Kits (Women(4-9; 35-40)) Cut-to-fit Style, easy to get the one fits your size(Women/ Men) Rechargeable wireless foot warmer, no need to get any cords or straps around your foot or ankle Adjustable remote control: 3 temperature settings to warm up your feet H Mode -- 45-50/ M Mode -- 35-40/ L Mode -- 25-30 Lithium ion batteries: 1800mAh; 3.0V-4.2V