Alpinestars Bionic Knee Guards , Distinct Name: Black/Red, Size: OSFM, Gender: Mens/Unisex 650633134XL Articulated knee design Impact-resistant, ventilated thermoplast shell with aluminumreinforced knee cup Fits knee and the side of the bike with asymmetrical form Comfortable Lycra; liner and removable impact-resistant Bio-Foam padding Adjustable hook-and-loop fastening straps