Small/Large size-specific for optimal shoe/pedal interface Reinforced composite body is lightweight, improves deflection and reduces hangup during rock strikes Concave platform for secure foothold (13.515.5mm thin) 10 replaceable traction pins Premium bearings and seal system Small recommended for size 510 (37-43). Large recommended for size 10-15 (43-49) 5 year warranty Third party online sales strictly prohibited by manufacturer