Forged and machined 6061-T6 aluminum platform Concave platform for secure foothold; 1113mm thin profile Premium bearings and seal system 10 adjustable traction pins per side Offered in small (100x100mm) and large (114x111mm) sizes for optimal shoepedal interface Small recommended for size 510 US (37-43). Large recommended for size 10-15 US (43-49) 5 year warranty