These Poly Inserts work great with the Slap Tattooers (#140026-K, #140030-K and #140031, sold separately). 1" in length.
works like a number set should
Fit fine in my hog slapper was sharp and made the mark needed. Some fit a bit tight from a casting protrusion but was easily fixed scraping it off with a knife. Expected something a bit flimsy feeling since it was plastic but was surprised they were very solid feeling. Since they are plastic the ink did stain them after use but not really a problem.