Castelli’s NanoFlex+ Legwarmers have an insert on the back in Nano Light fabric to help them bend around your knee better while keeping all the water protection intact. These legwarmers are more comfortable due to more flexibility, and in a slightly more compact package Features:Water-resistant thermal and breathable Nano Flex fabric Nano Light insert on back for extra stretch, bringing better fit and comfort Double-sided silicone grippers to keep the warmers in place ankle zips (leg warmers)Weight: 136g (pair)Technologies:Nano Flex: Exclusively engineered by Castelli, NanoFlex consists of Thermoflex fabric with millions of tiny silicone nanofilaments on the surface to create the most water-repellent finish ever. In wet conditions, water droplets simply bounce off the fabric without leaving a trace. The silicone nanofilaments also trap a layer of air between them for excellent insulation and prevent water from soaking through to the fabric underneath. In dry conditions, Nanoflex provides the same warmth and feel of regular Thermoflex fabric. NanoFlex is not completely waterproof but maintains full stretch, breathability and freedom of movement for weatherproof protection with un-compromised performance in all conditions Buy Castelli Clothing from Chain Reaction Cycles, the World's Largest Online Bike Store.