This external binding was designed specifically for use with Byerly's System line of boots. It features GX3 construction, making it lightweight and extremely strong. The articulating high-back allows for greater support and moves with a rider's leg to ensure a full range of rear motion. Adjustable ankle and toe straps are built with maximum retention in mind. Riders stand directly on the board, which means their energy is transferred directly to the board. Sizes: S/M(7-9), L/XL(10-13).