The Louis Garneau Arm Warmers feature HeatMaxx fabric that has a soft brushed inside to wick moisture while retaining heat. The biceps silicone grippers hold these warmers in place yet they're easily removed and stashed in a pocket or pack when things warm up. HeatMaxx: 4-way stretch opaque construction knit with brushed back. Biceps silicone grippers. Flatlock seams. Reflective accents. UPF/SPF 50. Imported.