We have always been of the opinion that the perfect longboard kneepad needs to be a slimline hardcap - small, light, solid and out of the way, but giving good protection against abrasion injuries. These Pro-Tec Kneepads fit the bill just right, with enough strapping to avoid slippages, and coming in at a decent price too. A great pad for keeping your knees safe! Tough Cordura construction with comfortable neoprene backing and durable plastic caps. These pads also feature: Ballistic Nylon New Rivet Design Diamond Grip Pull Tabs Locked"™ In Eva Cup Below is a sizing chart that will help you choose the right size pad for you. You will see there are two measurements (A&B)for each size. Measure in the following way for each point Point A :Measure circumference of the thigh four inches up from center of the kneePoint B:Measure circumference of the lower leg four inches below the center of the knee. Size X-Small Small Medium Large X-Large A Inches 9-11 12-14 15-17 18-20 21-23 CM 23-28 30-36 38-43 46-51 53-58 B Inches 6.5-8 9-11 11-13 14-16 17-19 CM 16-20 23-28 19-33 36-41 43-48 *Note Youth small will appear slightly different to image shown as they only have 2 rivets in the hard cap due to the size of the pad* If you have any problem using this guide please contact us on 0117 9332833. We will be happy to help.