A warm layer for before and after your session, the Nike Dri-FIT Crew gives you a soft, comfortable feel with double-knit fabric in a 1/2-zip design that goes on easily over your practice clothes. It's made with at least 75% sustainable materials, using a blend of both recycled polyester and organic cotton fibers. The blend is at least 10% recycled fibers or at least 10% organic cotton fibers.