Choose Nano Flex for warmers that are great in cool, dry conditions, such as for those in-between days when there is likely to be a large enough fluctuation in temperature or effort to require warmers that can be worn or removed as required. These warmers also offer some extra protection and warmth in wet conditions thanks to Castelli\\\'s proprietary Nano Flex fabric. These knee warmers have been part of the Nano Flex collection for seven years, and now, they have finally found a way to improve them. Castelli added an insert on the back in Nano Light fabric to help them bend around your knee better while keeping all the water protection. More comfort due to more flexibility, and in a slightly more compact package. Key Features Utilises Castelli\\\'s proprietary Water-resistant thermal and breathable Nano Flex fabric Double-sided silicone grippers to keep the warmers in place Flat-lock stitching with single seam for improved comfort About CastelliCastelli traces its roots back to a fine tailor (Vitore Gianni) in the heart of Milan, founded in 1876. Through the years, Vittore Gianni clothed AC Milan, Juventus and the Milan Ballet. The first cycling clothing was made in the 1910\\\"s for the world champion and five-time Giro champion Alfredo Binda. Castelli innovated the first aerodynamic Lycra shorts in 1977 which were used in racing and for public sales. Castelli\\\'s single-minded mission Is to make the most innovative clothing for the cyclists seeking maximum performance. Over the past decade, Castelli have led essentially every performance innovation in cycling clothing. Arm and Leg Warmers Buying Guide