29Pcs ER40 Spring Collet Set Precision Milling Lathe CNC Chuck Bit Holder Tool. 29 PCS PRECISION ER40 COLLETS SET, including: 1/8″, 5/32″, 3/16″, 7/32″, 1/4″, 9/32″, 5/16″, 11/32″, 3/8″, 13/32″, 7/16″, 15/32″, 1/2″, 17/32″, 9/16″, 19/32″, 5/8″, 21/32″, 11/16″, 23/32″, 3/4″, 25/32″, 13/16″, 27/32″, 7/8″, 29/32″, 15/16″, 31/32″, 1.