This vest maintains warmth by absorbing moisture and converting it into heat. ⭐︎Inner Material: Polyester sheet (Black Silica) ⭐︎Outer Fabric: Aluminum-coated polyester 100% ⭐︎Lining: Heat-retaining polyester 100% ⭐︎Filling: Polyester 70% / Moisture-absorbing and heat-generating fiber 30% This vest achieves high insulation and heat retention through the combination of the above materials. With its stylish and fashionable design, it can be worn for sports, leisure, town use, and more. It's also great that you can wash it at home♪ Unused, only tried on. Thank you.