Here are the details: Jumbo Flat Jaw Set of (4) plates. Precision machined from steel. For use on lathes with 10" swing or larger. Used to finish the bottom of bowls and plates up to 81/4" in diameter when used with PSI Utility Grip chucks, Barracuda chucks, and the Mini Grip chuck. Includes (8) 1/2" long rubber coated pins (grips)