THERM-IC S-Pack 700 B Heated Socks BatteriesHeated leather mittens with PrimaLoft insulation technology to guarantee insulation and impermeability. With 3 heat settings to ensure staying warm for up to 10 hours. Specifications: Genuine goats leather: soft and sturdy 3 heat settings: for even, gentle heat distribution Ultra light lithium ion battery offering up to 10 hours of heat Heat spreads 360 around the fingers and the top of the hand Membrane 10K 10K : impermeable and breathable Compatible