Features HeatMaxx fabric that has a soft brushed inside to wick moisture while retaining heat. Materials: 86% nylon, 14% spandex Biceps silicone grippers hold warmers in place Flatlock seams to eliminate irritation and reduce chafing Fabric offers UPF/SPF 50 sun protection Opaque construction with brushed back to retain body heat Reflective accents for added visibility Specifications Defined Color Black Size Small