Calculated by diameter, not radius, but inches. There are 1 1.5 2 2.5 3 4 5 6 8 10 12, which are all inches, 2.5 centimeters per inch, and 1-2 are small wheels with a width of about 2 centimeters.

345 has two types: light and heavy, light load 100-150 kg, heavy 200-500 kg, and special load 1 ton.

810 12, etc. are all heavy-duty wheels. Choose wheels according to your usage, such as full height, load capacity, use environment, etc.