Long a favorite style of warmer wearers everywhere, the Castelli Thermoflex series has been lauded for it's comfort and protection. With the Thermoflex+ series, the Italian company has improved the already good fit and freedom of movement without sacrificing the protection level. Thermoflex+ Knee Warmers are perfect for rides or segments of rides that take place in the mid-40's to mid-60's Fahrenheit when cool air and/or precipitation are in play.

The proven Castelli Nano Flex system takes a soft, stretchy, lightweight, breathable, insulating fleece fabric and treats it with coating featuring millions of nanofilaments. The resulting finish repels water completely, instantly beading it up and shedding it. Well proven in warmers, bibs, tights, and other pieces where garment flexibility and protection are desired, Nano Flex blocks wind and repels water with ease.

The big addition to the Thermoflex+ Knee Warmer is the addition of a back side panel of the lighter, even more flexible and comfortable Nano Light material, which has less insulation, but the same water repellent capability. Out of the wind, behind the knee you don't need more insulation, what you want is complete freedom of movement, zero bulk, and great fit without too much tension. Nano Light gets the job done and makes the Thermoflex+ a true upgrade on an already fantastic warmer.

Fit and finish are fully anatomic, allowing you to forget you are augmenting your clothing with a warmer. Castelli employs a double silicone gripper system - inside and outside the warmer so the piece will hold in place on the skin, as well as under your shorts or bibs, for maximum retention no matter how hard you go, no matter how wet it gets.