CMT 184.132.00 ER40 Precision Collet, 1/2-Inch Diameter ER40 Precision collet for 1/2-Inch Shank Diameters. Fits CMT chucks 183.201 and 183.310. Fits most tapered spindle noses. Wide clamping tolerance +0-0,7mm. Suitable to most of the conical chucks.