THIS IS A BUCK MODEL 2154R LATHE CHUCK FEATURING A 3-JAW ADJUST-TRU DESIGN, ENGINEERED FOR PRECISION TASKS. THE CHUCK HAS A 15-INCH DIAMETER AND INCLUDES A 4-INCH THROUGH HOLE (BORE). IT IS EQUIPPED WITH A D1-8 BACKPLATE AND HAS A TOTAL OF 3 JAWS. THE MANUFACTURER IS BUCK.