vi3tishduy, ross means 50mm and 52mm in diameter. The width is immaterial in essence, as you can cut it to whatever width you want.
You might find when it doesn't fit even with heat, you have to grind off the inner lip of the wheel to fit it on. I had to with my PSE rims. Its relatively easy, you can do it with a hand file if you can be bothered, but a bench grinder is good. Just don't think you can put regular tyres on after that, that's all.
If the ABS is too big, what some guys have done (didn't dave do it ross?) is tape around the wheel until it was a snug fit, then just push it on.