The Castelli Nano Flex 3G Arm Warmers are a stalwart of your winter cycling kit – rain repellent, windproof, warming and luxuriously comfortable, this latest evolution of the Nano Flex technology is Castelli’s best yet. The Nano Flex 3G fabric used across these arm warmers utilises a combination of newly updated durable water repellent (DWR) treatment and mechanical heat treatment to give previously unheard-of levels of rain protection. Light rain beads off the fabric, keeping you dry when those inevitable rainy spells descend. The flat-lock stitching and single-seam construction keep the profile of the warmers low and the stretch is optimised for maximal freedom of movement. A dual-sided silicone gripper at the upper end secures the warmers in place. The compact size of the warmers makes them easy to stuff into rear pockets when conditions lighten up. On the inside of the Nano Flex 3G fabric, a super soft finish and the optimal loft have been achieved through Castelli’s meticulous research and development. The fabric feels phenomenally comfortable against the skin and the loft traps just the right amount of air above the skin to keep your heat regulated over a wide range of autumn and winter conditions. Features Newly updated Nano Flex 3G fabric for exceptional warmth, softness and protection from the rain. Minimal seam construction for aesthetic versatility and freedom of movement. Easily packable into a pocket. Highly breathable. Optimal temperature range is 8 ̊C – 20 ̊C.