Castelli Flanders 2 High Neck Warmer Base Layer When the temperature drops and your breath hangs in the air, the Castelli Flanders 2 High Neck Warmer Base Layer becomes an essential part of your winter cycling kit. Designed for deep winter riding, this is Castelli’s warmest synthetic base layer, made from SottoZero multi-denier 100% polyester fleece fabric. It delivers exceptional insulation and moisture-wicking, keeping your core warm and dry in freezing conditions. The built-in high neck warmer adds an extra layer of protection, doubling as a face mask or helmet liner to shield you from biting winds and icy air. With thoughtful details like flat Merrow stitching to prevent chafing and a mesh armpit insert for improved breathability, the Flanders 2 Base Layer is crafted for comfort during high-effort rides in sub-zero temperatures. Designed for use between -4°C and 6°C, it pairs seamlessly under your winter jacket to create a defence against the harshest conditions.