Analyzes shoe size and outsole surface and adopts pedal size for different size range. Large is recommended for those who are 43 or larger shoes. Adopts a new shape that strengthens the spindle and prevents it from getting caught on rocks, and other obstacles. Shape and thickness to minimize weight and contact with obstacles while maximizing pedal treads. Concave platform for weight reduction and increased tread stability Uses the same bearing & seal structure as STAMP7 using igus LL-Glide bushings on the outer and inner sides for superior durability. Equipped with 10 interchangeable traction pins. (*The pin uses a long one that penetrates both sides. )