What Our Gearhead(R) Experts Are Saying:"The X4 Knee Guards are a great blend of comfort and protection. The SmartFlex padding stays flexible as I pedal but hardens instantly on impact, giving me confidence on rough descents. The slip-on design with grippers keeps them in place, and the breathable fabric keeps my knees cool, even on long rides."When we're pushing our limits on the trail, we need knee protection that moves with us. The X4 Knee Guards feature SmartFlex technology, staying flexible while riding but instantly hardening on impact for reliable crash protection. The pre-curved ergonomic design ensures a low-profile fit that won't feel bulky, while internal vent channels improve airflow to keep us cool. A wide red gripper and textured bottom grip prevent slipping, so we can focus on the ride-whether it's technical trails, all-mountain terrain, or cross-country adventures.