So I was a bit hesitant to purchase this because I don't have the exact models the description says it works for.  I have the 7346sp, which is the sander and polisher.  I got it to fit after loosening up the adjustment screw all the way, and used a little brute force to get it on.  I have a Rigid shop vac, and the hose or supplied adapters didn't fit.  Went to the store and got the nipple looking adapter for $10 and it fit.  Dont order the adapter online.  It cost 2-3xs the price at the store.