The Gray Ops CNC Brass Marker is quick and easy. Marks in rim of case, across primer, and on body of case. Use one, or all 3 marker locations at the same time. Slotted design holds onto rim of case through the entire marking process for perfectly placed lines. Accepts any standard sharpie style marker, and secure them at the correct height with the supplied thumb screws.Note: Magnum does not work with 338 Lapua based casesFeatures223 (223, 300 Blackout)Standard .473 BF - (6BR, 6.5x47, 308, ect.) Magnum .540 BF- (6.5 SAUM, 6.5PRC) Slotted design holds onto rim of case Accepts any standard sharpie style markerMarks in rim of case, across primer, and on body of case