Quoted from the Yonex HP ↓↓↓ Very Cool Cool sensation of -3°C thanks to Xylitol. Natural Xylitol, derived from trees and plants, is used in the fabric. It reacts with sweat to absorb heat, lowering the temperature inside the garment by approximately 3°C. Yellow is also available. If you buy two, I'll sell them for 3000 yen (＾＾)