Sizing is as follows: Extra Small Fits 6 inches - 7 inchesSmall Fits 8 inches - 9 inches Medium Fits 10 inches - 11 inches Large Fits 11 inches - 12 inches Extra Large Fits 13 inches - 14 inches 187 Killer Elbow Pads - Made by 187 Killer Pads for Roller Derby Skaters, Roller & Inline Skating, and Skateboarders - Designed to fit your arm not a 2x4 - Tapered finish & streamline design for less bulk - Contoured shape with seamless interiors for amazing fit & comfort - Double stitching and high-strength ballistic nylon for durability - Superior interior foam and form-fitting riveted caps for performance