Riding hard is synonymous with crashing, which means the Leatt Airflex Knee Guard is synonymous with keeping your knees from making painful contact with the ground when you take a spill. Synonyms aside, the Airflex is a seriously light knee pad, at under eight ounces per pair, and the sleeve is made from moisture-wicking and ultra-stretchy MoistureCool fabric, to keep your knee pits dry and your pads in place. The padding, Armorgel, is a unique substance that's soft and pliable until impact, at which point it hardens almost instantly to protect your 'caps from crashes and tumbles and to keep your socks free of blood.