Metzeler ME 880 Marathon is a winter tyre made in total of 30 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 200/50 R18 is 60mm wider than the narrowest dimension (140) and -80mm narrower than the widest one (120). This tyre profile of 50 means the sidewall height of the tyre is 50% of the tyre width (200mm), which results in 100mm sidewall height. In 200/50 R18, there are 2 possible speed indexes for Metzeler ME 880 Marathon - "H","W", which are good for speeds up to 210, 270 km/h.