Castelli Nano Flex 3G

Nano Flex arm warmers for all conditions

Choose Nano Flex if you're looking for a pair of arm warmers that are great for dry days, but also provide a little extra protection in the rain.
Castelli has invented the category of thermal fabrics to protect you from water: the proprietary Nano Flex is often imitated, but never reproduced to perfection.


  • Water-repellent, thermal and breathable Nano Flex fabric.
  • Flat seams.
  • Silicone elastic on both sides.
  • For temperatures: 8°-20°C / 46°-68°F.


Nano Flex

Exclusively engineered by Castelli. They took their thermal fleecy stretch Thermoflex fabric and coat it with millions of tiny nanofilaments to create the most water-repellent fabric finish ever. Drops of water stay as spherical balls on top of the fabric or bounce off the fabric without leaving a trace.