The Castelli Thermoflex 2 Arm Warmers are designed to take some of the sting out of cold-weather cycling while remaining as comfortable and secure as possible. The Thermoflex fleece fabric is warm and stretchy with a soft brushed interior, and offers surprising wind resistance and moisture management capability. Castelli pays careful attention to the construction, employing a one-piece design with flat-lock seams that virtually eliminates irritation or discomfort--even on longer rides. An elastic cuff with silicone gripper prevents slippage and won't pinch your skin, so you can keep both hands on the bars and focus on the road ahead. And while they may lack the wet weather protection of Castelli's Nano Flex warmers, the Thermoflex 2 Arm Warmers provide a bit more insulation for those chilly spring and fall days.