Motorbike. The size will always be a combination of either 4.10-4 or 410-4 or 4.10/3.50-4 or 410/350-4 or 3.50-4 or 350-4. The last digit of 4 being the 4" (101mm) wheel rim size. A high quality Tyre made to fit to the front or rear of Mini BMX bikes.
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