Continental Contisportcontact 3 is a tyre made in total of 55 sizes, ranging from R16 to R16 - this particular dimension is R17, which means it fits to a 17 inch/431.8mm diameter wheel. 225/45 R17 is 30mm wider than the narrowest dimension (195) and 60mm narrower than the widest one (285). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (225mm), which results in 101.25mm sidewall height. In 225/45 R17, there are 3 possible speed indexes for Continental Contisportcontact 3 - "V","W","Y", which are good for speeds up to 240, 270, 300 km/h.
