Wedge ensures the correct distribution of pressure across the lower leg, which prevents knee and back complaints. Takes on the shape of the users knee after a while to offer greater comfort, flexibility and ergonomics. Broad, flat surface for extra stability. Non-Marking Knee Support Hook & Loop Elastic Strap Model: Original Wear-Resistant Water-Repellent Replaceable Inlay Non-Pinch Straps Non-Marking Knee Support Hook & Loop Elastic Strap Model: Original Wear-Resistant Water-Repellent Replaceable Inlay Non-Pinch Straps