This Chuck has a direct thread 1-1/4 by 8 tpi . A circular recess in the rear plate has three counter weights than can rotate 360 deg, allowing to balance the workpiece. The cupchuck pick up at the front has three M8 grab screws to allow to rotate and secure the cup and faceplate to your required position. Included with the chuck are: a 40mm Cup Chuck, the necessary Allen T-bars and keys and an Escoulen Gauge.