Used in conjunction with FST Footpads, FST System Blocks can be positioned and secured to help keep your foot in place while riding rough terrain. Different styles of Blocks allow you to configure your stance to exactly what's most comfortable for you and complements your riding style. > The Nub (Pro). Low and relaxed. > The Ledge (Pro). Mid-height, medium engagement. > The Crux Pro. Tallest for maximum engagement. Pro models are over-molded with rubber for additional comfort and control. Compatible with Onewheel FST Footpads only. Each order includes 2 Blocks.