Rear chuck adaptor for metal lathe. This adaptor will mount to the rear of a metal lathe spindle and has threads to attach a 3 or 4 jaw pro series chuck to add rear spindle support. There are 4 adjustment screws to dial in the rear chuck to run perfectly concentric to the front chuck. The through hole is 1.38" and the rear cavity will accept a spindle up to 2 2" and 1 " deep