Nano Flex for the ultimate warmer: warm and comfortable in dry conditions, water repellent in damp conditions, and still warm in extreme conditions.

Choose Nano Flex for warmers that are great in dry conditions but also give some extra protection and warmth in wet conditions. Castelli invented the category of water-protective thermal fabrics, and their proprietary Nano Flex is often imitated but never equaled. No compromises for any conditions.

Product features
- Water-repellent thermal and breathable Nano Flex fabric
- Flat-lock stitching with single seam
- Double-sided silicone grippers to keep warmers in place