ProKnits are engineered for a high-performance lifestyle yet comfortable enough for day-to-day use. Each band is lined with high-tenacity filaments that form an active layer between the band and the surface of the skin to maximize breathability while absorbing sweat. We also added a rubber film to keep the band secure on the WHOOP device. Fits both the WHOOP Strap 2.0 and 3.0. Clasp is not included.