This Special Edition C-Series package includes both the chuck system (CUG3418CC) and a set of 8-1/4" Flat Jaws (CJAWXL); Heavy duty chrome-plated self-centering chuck will hold your work tight & secure on midi/full size woodworking lathes Chuck body is pre-threaded to 1" x 8tpi, weighs 4 pounds, and is 4" in diameter; Includes a 3/4" x 16tpi headstock spindle adaptor #1 step jaws 3/32" to 1-7/8" External & 11/32" to 3-3/8" Internal; #2 round jaws 1-1/2" to 3-1/8" External & 2" to 3-7/8" Internal; Also includes a screw chuck, allen wrench, and a set of tightening levers 8-1/4" Flat Jaws will grip workpieces from 2-3/4" to 8-1/4" diameter; (7) positions for bowl rim placement; Made from cast aluminum; Weighs 1.50 pounds; Ideal for finishing and polishing woodturning bowl and plate bottoms Includes (16) soft rubber gripper bumper pins in two lengths to securely hold your workpiece: (8) 1/2" & (8) 3/4"; Pins have a 6mm thread; Also includes a allen wrench