Nike Men's Power Essential Running Tights synthetic Dri-FIT fabric helps keep you dry and comfortable. Mesh back knee panels for targeted breathability. Elastic waist with interior drawcord for a snug, adjustable fit. Zip pocket at back waist. Flat seams help minimize chafing. Zip vents at hem for easy on-and-off. Contrast side panels. Fabric: Body: Dri-FIT 92% polyester/8% spandex. Back knee panels: Dri-FIT 80% recycled polyester/20% spandex.