Troy Lee Designs Speed Elbow Sleeves are an ultra-lightweight & flexible full arm sleeve with 4mm thick D3O padding around the elbow & into the forearm. The low weight & breathable nature of these pads make them ideal for day-long adventures. Features D3O® 4mm ultra-lightweight & flexible elbow pad Full-length sleeve with silicone grippers prevent slipping Breathable mesh panel for all-day riding comfort Durable, abrasion-resistant elbow panel Reflective logos 1x Pair Size Measure wrist circumference behind wrist bone for “wrist” & above the bicep at the smallest point for “upper bicep”. Measurements should fall into one of the following size categories: Size XS/SM/LXL/XXLWrist cm 15-17.517.5-2020-22.5 Upper Bicep cm 25.5-30.530.5-35.535.5-40.5 Rider Weight 70-140lbs 140-180lbs 180-220lbs Rider Weight 32-63kg 63-82kg 82-100kg The elbow pad should not be loose in any area. Make sure there are no gaps between the product & arm & that the openings are snug.