Description Specification Size Chart Fleece arm warmer featuring flatlock stitching ideal for cool weather conditions... training rides or early morning race starts.CS WinterFleece™ is an incredibly lightweight and warm brushed fleece. It's a single-sided fleece, which means that only the inside of the arm warmer is fleece-lined. The outside has a smooth finish for improved aerodynamics. CS WinterFleece™ fabric - Thermal "Roubaix" lycra with brushed fleece lining and high stretch for maximum movement. Flatlock exposed stitch for improved fit and comfort. Designed to discreetly hide and fit under your jersey sleeves. Silicone gripper placed inside the elastic band to aid in holding the sleeve in place around the bicep. Unisex Sizing. Size Wrist (inch) Bicep (inch) XS 5 9 S 5.5 9.75 M 6 10.5 L 6.5 11.25 XL 7 12