YONEX warm-up wear with HEAT CAPSULE function to maintain body temperature using infrared rays. - Brand: YONEX - Color: Blue/White/Black - Size: S - Function: HEAT CAPSULE - Features: Stores heat with infrared rays Thank you for viewing. My middle school child was going to use this, but they joined a different club, so it was only worn once or twice and is hardly used. However, please note that the name is written on the collar.