The Troy Lee Designs T-Bone Lightweight Knee Guards are super lightweight & easy to wear protection with a triple layer of stacked protection (EVA, TPR & memory foam) works together offering protection far superior to the weight of the product.T-Bones from Troy Lee Designs will protect your knees when you run out of talent, & give you the confidence to ride at a higher level. Features Moulded EVA outer shell with ballistic nylon cover Knee cup consists of a combination stack of EVA, TPR & memory foam Ergonomically contoured with two elastic Velcro closures & internal silicone grippers Lightweight & low profile 1x Pair CE certified to EN13688:2013 Sizing Take measurements 10 cm above the knee CENTER for Lower Thigh measurement & 15 cm below knee CENTER for Calf measurement. Measurements should fall into one of the following size categories: Size XS/SM/LXL/XXLLower Thigh (inch)15-17"16.5-18.5"18-21" Calf (inch)13-14.5"14.5-17"15-18" Rider Weight (lbs)70-140140-180180-220 Rider Weight (kg)32-6363-8282-100 The knee pad should not be loose in any area. Make sure there are no gaps between pad & leg, & the openings are snug. The kneepad foam padding shall be placed directly over the kneecap.