Gripmax SureGrip Pro Sport 305/30 R21

Gripmax SureGrip Pro Sport is a summer tyre made in total of 119 sizes, ranging from R18 to R18 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 305/30 R21 is 100mm wider than the narrowest dimension (205) and -10mm narrower than the widest one (295). This tyre profile of 30 means the sidewall height of the tyre is 30% of the tyre width (305mm), which results in 91.5mm sidewall height.