Criterion TABH-250B Tenth Adjusting Boring Head 1/2 Capacity CAT40 1 1/2-18 THD. Good used clean condition with smooth adjustments.
There are 2 available, 1 per order. One has a Criterion CB3-CV40 shank, the other has a Parlec C40-15BH188. Both are the same 1 1/2-18 thread and will accept other shank sizes matching that thread.
Please review all photos to determine condition and identification.