Louis Garneau's Knee Warmers 2 features HeatMaxx fabric that has a soft brushed inside to wick moisture while retaining heat. Features: Materials: 86% nylon, 14% spandex Flatlock seams to eliminate irritation and reduce chafing Fabric offers UPF/SPF 50 sun protection Silicone grippers at the thigh holds warmers in place Opaque construction with brushed back to retain body heat Reflective accents for added visibility