These are Matrix kyosho tire sets (4 tires) that you can reserve for open practice. The tires are the same as the controlled tires: 37 shore fronts and 40 shore rears and they come pre-trued at 62 mm fronts and 64 mm rears. You can purchase as many as you want.
Practice Tires Matrix 1/10 Worlds Spec
No shipping available, your order will be waiting for you at the Track