Insulated, flame resistant, water resistant cover for battery on E-Bike. Keeping your battery at normal operating temperatures improves performance and battery life. Also, protects the battery from rain, sun, and elements while on car rack. - Made with water-resistant nylon - polyester on outside for excellent water resistance. - Inner material made with fire and flame-resistant materials (passes FMVSS 302 Flame Test) - Fits surface-mounted battery and is compatible with Bosch PowerPack, Shimano Steps, Samsung, Yamaha - Pocket on top to keep small items close at hand. - Mounts with drawstring and hook and loop.