Cool, just saw an ST3 Super Thumb in my local shop. Any idea if these work? I haven't seen any "A" models though.My Adco Super Thumb 1 is a bit too tight side-to-side while my Super Thumb 2 is very sloppy in both directions. The ST 1 should fit well after a few minutes work with a file. On the other hand, Adco has added an "A" suffix to their ST1 and ST2 model designations, so their current offerings may fit a bit differently. The selling price should be about $6.