Gripmax SureGrip Pro Winter 305/40 R20

Gripmax SureGrip Pro Winter is a winter tyre made in total of 35 sizes, ranging from R17 to R17 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 305/40 R20 is 130mm wider than the narrowest dimension (175) and 30mm narrower than the widest one (335). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (305mm), which results in 122mm sidewall height.