The Leatt Endurance 3. 0 MTB helmet is a lightweight helmet for XC and gravel riders with rotational impact protection built in. 360deg Turbine Technology discs let the helmet move slightly on the head on impact, which helps reduce rotational forces. In-molded PowerBridge and impact foam help absorb high-speed impacts. What Our Gearhead(R) Experts Are Saying:"On a long climb in the heat, air keeps moving through the helmet even when I'm crawling, so it never turns into a heat trap at low speed. The liner wicks sweat off my forehead, so it stays out of my eyes."