Dummy rounds are a critical item for effective firearms training. Everyone who carries a gun should have them- and use them regularly as part of their training regimen. The ones by ST Action Pro are, by far, the the best that we've used. Unlike all-plastic dummy rounds, these don't break or wear in a way that causes failures to extract and other unintended malfunctions (not that that's always a bad thing).
We package these in bags of 5 rounds.