The Dual Fit Design is compatible with SPD-SL and SPD shoes. It is made from PU-coated recycled polyester and fleece, which are significantly lighter, warmer, and more flexible compared to synthetic rubber based on petroleum. YKK AquaGuard® NATULON® water-repellent zipper with a tape made from rPET. A Velcro closure on the underside allows for easy on and off. The reinforced material at the toes ensures significantly higher walking comfort.