Vredestein Wintrac Pro is a winter tyre made in total of 121 sizes, ranging from R17 to R17 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 285/45 R21 is 90mm wider than the narrowest dimension (195) and 40mm narrower than the widest one (325). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (285mm), which results in 128.25mm sidewall height. In 285/45 R21, there is only one possible speed index for Vredestein Wintrac Pro - "Y", which is good for speeds up to 300 km/h. In 285/45 R21, Wintrac Pro usually competes against Blizzak LM-005, which is a tyre from Bridgestone with a rating of 88%, compared to 62% of the Vredestein in question.