Yep, it's a slide hammer, which is what the factory tool is. I have never seen a puller like you describe for the prechambers. The slide hammer works pretty well, although it takes a number of hits on an old prechamber. After I cleaned mine up, they dropped into a new head with no force needed (didn't have to be pressed, or even tapped, into place). The item pictured above is hand made by a machine shop in SoCal with top quality tool steel - nice stuff. I've got one each I'm keeping, those are my extra set that I'd like to get out of my garage, lol...