YONEX Heat Capsule Windbreaker Pullover Sportswear Badminton Tennis Cold Protection Heat Capsule is a heat-retaining and heat-generating material developed by Yonex. Infrared absorbers are woven into the fiber surface and between the fibers, and it has the function of converting infrared rays into heat. The generated heat is retained within the fibers that contain a lot of air, which keeps the temperature inside the clothing high, resulting in a surface temperature difference of about 3 to 7°C compared to conventional cold protection materials. This is the perfect item for sports in the winter. Size L Width 55cm Sleeve length 61cm Length 70cm Please refrain from purchasing if you are overly concerned about details.