Description187 Slim Knee Pads are a 3 year development to achieve the slim fitting low-profile design, while maintaining it’s durability and protection.FEATURES– Fusion groove Channel with Memory Foam System to lock the pad into the ideal position – Streamlined slide-on design that hugs firmly and comfortably with minimal bulk – Light weight fast-drying seamless interior finish – Ballistic Nylon with industrial weight stitching ensures durabilityTo ensure a perfect knee pad fit, measure circumference of extended knee and match to the size listed below:X-Large: 17 – 20in