Jewelry Engraving Fixer Sharpening Angle Device, High Precise Tools Dual Angle Sharpener Angler for Jewelry, Stainless Steel Angle Ring Precise Engraving Grinding Machine Fits Workbenches

I had to use a 1/4" drill bit to open up the collet hole to accept the typical black GRS QC holders. Originally it was too small, but that drill bit with a little sanding worked great. Also, I had to remove the black plastic knob (used to rotate the graver's face and main angles). I think I had to remove one of the two grub screws so the GRS holder could actually hit the indexing spot. Then re-install the black knob but only partially otherwise the GRS holders are too long and it can't reach the indexing spot.All-in-all, with those modifications it works pretty damn well. Custom made 90s, 100s, 105s, 120s, flats, etc. It definitely works. I've used the real deal and this is close enough for the money you'll save. Especially if you're a beginner or just testing the expensive waters of engraving tools. 4 stars because it wasn't ready to go out of the box.