do the Duncan mod spacers only work on Offstring throws? or can you put them in let’s say, the Butterfly XT? and are they worth it?
LOL, 1: they are for the old Duncan offstrings, 2: no, 3: no
Here some more on Mod Spacers
The Duncan Pro Z comes with mod spacers, a C size Concave bearing and a A size bearing…so if you want mod spacers, it might be worth tracking down a new Pro Z.