Keep the water out and stay fast. The Speed Skin Silicone Bootie by Sportful is made from a silicone-coated Lycra that is totally windproof and waterproof while being close-flitting and cut high for minimal flapping and maximum aerodynamics. Reduced seams aid aerodynamics too, while eliminating any weak spots where road spray could enter the overshoe. A sealed ankle stops water getting in through the top opening. Ideal for wet race days, or anyone seeking an advantage.