Washable: Can be washed to keep them fresh. Heated insoles: Get a pair of heated insoles. Extra warm: The carbon fiber heated insoles can be heated to about 50°C - perfect for toasty feet. USB rechargeable: Includes a USB charging cable which can be connected to your computer, power bank power supply or adapter power supply. Two options: Men's size UK 6-9 | Women's size UK 2.5-6 (simply cut the insoles to your desired size). Suitable for: Slip inside your shoes, boots, trainers, wellies or slippers for warm and toasty toes! | USB Rechargeable Heated Insoles | Wowcher