I've had several (well, at least three) multi-position carriage stops and have come to the conclusion that they are one of the most machine specific accessories around. And unlike things like steady rests, it's highly unlikely that anyone who didn't have the or a machine that it fit could determine whether it will fit another machine that he doesn't have handy to check. And the more stations (positions) one has, the worse the problem would be. I had a triple one once on which only two stations were usable, and to use it, you had to get the long stop and the short stop in the right order.
As someone else mentioned earlier, dedicated turret lathes, bed turrets and tailstock turrets generally have their own stops. What the multi-position carriage stops are made for (or at least one thing they're made for) is for use on lathes with double tool-post cross slides, which typically come with a 4-way turret tool post.