For sale is a 12 Inch diameter, three jaw, Adjust Tru Buck Chuck. This chuck is huge, so I showed it in comparison with a regular size beer can (not included).
This chuck has a L0 (LO, L-O) mount. There is light rust near the mount, but nothing really major. I show it on pictures.
At some point I paid big bucks for it, but discovered that it is too big for my own use. This chuck operates smoothly and includes a square T handle key.