A couple of companies sell it, but Mr Gasket is who made it famous basically.
You go by the diameter of your damper ring. So if you have a 6.5" outer ring, that's the model you get.
Different manufacturers might use different colors, or different fonts, but the concept is the same no matter what.
Obviously because we're talking about degrees of a circle, the size rating of the tape should match the diameter (actually the circumference) pretty close. But frankly, if I had tape that was just slightly different from my application, I'd still use it.
The degree tick marks might be off slightly, but for most people's street use, a half of a degree one way or the other isn't going to make or break a tune.
The critical point is zero degrees, or TDC anyway. If you're persnickety about this kind of thing, you could align the desired degree mark (for instance, the 10° mark) with the pointer instead.
Paul