One of a kind, property of Ford at one time, stunning tool. No idea what it is used for but for the person looking for one this is the holy Grail. Can’t find any existing ones out there and very little info available on it. Beautiful tool and engineering. Unopened prior to myself opening to take pictures The AI description is below. The item 2902784 from Ingersoll Cutting Tools corresponds to a specific indexable BTA peripheral plus cartridge, part of the heavy-duty deep-hole drilling and tooling system. If you are looking for an Ingersoll counterbore, Ingersoll manufactures indexable and center-cutting counterbore tools typically cataloged under their 15C, 15S, and Chip Surfer series. 20mm BTA interface Item #94