On the inside of the Thermoflex 2 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. The discreet black embossed Castelli wordmark logos on these warmers is a nice touch and means that they can be worn with a wide range of jerseys. The dual-sided silicone gripper on the upper edge keeps the warmers securely in place whilst the single-seam construction and flatlock stitching contribute to a low-profile look and feel. Features Thermoflex 2 fabric for exceptional warmth and softness. Minimal seam construction for aesthetic versatility and freedom of movement. Easily packable into a pocket. Highly breathable but also insulating. Optimal temperature range is 8 ̊C – 18 ̊C.