Cyclists, this Sportful helmet liner is exactly what you need for those chilly morning rides! It's designed specifically to fit perfectly under your bike helmet without adding bulk or affecting the fit. The black color goes with everything and the 100% polyester material provides just the right amount of warmth without making you overheated. What's really cool is the ThermoDrytek material on the ears - that's where you feel the cold most, and this extra protection makes a huge difference. It's thin enough that you barely notice it's there, but warm enough to extend your riding season into colder weather. The cap wicks moisture away from your head too, so you stay dry and comfortable even during intense climbs. I've used mine down to about 40 degrees Fahrenheit and stayed perfectly comfortable. Fits under my regular helmet with no adjustments needed. If you're tired of cutting your cycling season short when temperatures drop, this little cap is an absolute must-have for your gear collection!