Choose Nano Flex for warmers that are great in dry conditions but also give some extra protection and warmth in wet conditions. We invented the category of water-protective thermal fabrics, and Castelli's proprietary Nano Flex is often imitated but never equaled. No compromises for any conditions.
Water-repellent thermal and breathable Nano Flex fabric
Flat-lock stitching with single seam
Double-sided silicone grippers to keep warmers in place