Product Name: Real Heat Heated Knit Cap & Neck Warmer - World's First! Heat Generation, Insulation, Windproof - Unisex Neck Warmer Brand: AmaFanshop Color: Gray (Neck Warmer) Size: Free Size ・Material Composition: Fleece 40%, Polyester 60% ・World's first triple effect: heat generation, insulation, and windproof - get through this winter! (Battery not included) ・Easy-to-use magnetic USB cable. Easy to attach and detach. ・Three-layer construction shuts out cold wind. ・Widely usable for running, cycling, motorcycling, skiing, mountain climbing, commuting, etc.