Polyester. MUST HAVE FOR OUTDOOR COOLING: It is powered by electricity and made of sunscreen material. It is the most practical and durable cooling device for outdoor cooling today. COOLING PRINCIPLE DESIGN: The air conditioned clothing is made of nano-grade sunscreen fiber fabric, UPF50+, which can block 99% of ultraviolet rays, light and comfortable. According to the principle of ergonomics heat dissipation, the fans are placed on both sides of the clothes, and the wind flows from the bottom to the top, blowing to every part of the body, so that you can feel the whole body cool. POWERFUL WIND & THREE-SPEED ADJUSTABLE: The jacket fan is made of brushless motor and 9 blades, smooth power, lightweight and portable. The unique oblique flow fan is designed with large air volume and low noise. And equipped with 3-speed adjustable wind speed, weak wind, medium wind, strong wind, allowing you to customize your cooling experience. Cool Vest Wearable Cooling Fan Vest, Air-conditioned Clothes