When I first got it I couldn't snap the bits into place. Called Revane, they couldn't help me. So I researched. I found that the striker bar would get stuck in the chuck when the drill bit had to rest to engage. So I used the pointed chisel that came with the package. I placed it as if to lock it, tapping the tip of the drill while holding the drill, which in turn drives the striker rod back into the drill just enough that the drill now locks (I call this a punch). bar because that's the technical name) but it's in the cartridge. As soon as I find out. I used it to remove the tiles from the bathroom floor and it works great. I'll buy a wide chisel, but still. In general I am very satisfied with the product and its price.