RCBS UNIVERSAL PRIMER ARM

Worked with my old Dillon open faced press with a little filling to fit. Needs 1/4 pin which is not provided to mount. Comes with large and small primer cups

Having 2 primers drop at a time when using my old primer arm to tap the button to get a primer to drop from the primer sleeve into the primer cup, but seeing no visible problem w/my old primer arm, I inserted the new RCBS primer arm & cup and found only 1 primer to drop at a time into the cup - as it should have been.
Problem solved.