I got an invite to call Vermonster and did so... he explained that there are some minor differences in some of the ILF risers, particularly the European ones. (also on the DAS risers, which have a bushing, but I think most folks know that..) Anyway, it's mostly a matter of precise fit... and if there is a problem fitting it, don't use it. I have several limbs from different makers... Kap, Win/Win, Flute (European) and Trad Tech. All have worked so far. Vermonster pointed out that on some the mounting angle may be a bit different from others, so the math of calculating what weight you're going to get may be off a bit. Sounds like a little common sense will handle it.