Our New X4 Knee Guards boasts a new SmartFlex pre-curved padding for extended coverage and an ergonomic, comfortable ride every time. These CE-1621-1 Level 1 certified guards have innovative heat management and ventilation systems to keep you cool and dry on the trails. Additional padding and as secure fit provide ultimate comfort and easy on-off, and throw it in the washing machine when you're done for the day. FEATURES: Featuring SmartFlex: Flexible pads that harden upon impact to absorb force and then immediately return to flexible state New pre-curved SmartFlex pad provides a flexible, ergonomic, and secure fit Internal pad geometry and molded vents optimize heat management Breathable compression fabric with enriched materials, including ribbed side paneling for added comfort CE-1621-1 Level 1 certification Interior top red gripper and textured elastic bottom gripper keep guards securely inplace Guards easily slip on, but molded fit reduces the need for frequent adjustments. Compression sleeves with grippers at the top and bottom to keep guards in place Extended coverage in critical areas for added protection. Machine washable