Inner diameter: 17.5 Depth: 28.0 Throat: 3.7 I acquired this, but I never used it. As shown in photos 4-6, the shank is warped and there are noticeable scratches on the rim, so the condition is poor. The shank may need to be adjusted with a tool, or it might be best to think of it as something to experiment with. Instant purchase OK.