ER collets Unique 8°taper design affords highest gripping power. True double angle, for extreme concentricity. 16 jaws giving powerful gripping and parallel clamping. A unique self-releasing system is built into the collet and claming nut to eliminate cutting tools sticking in collets. TypeABER1111.5mm18mmER1617mm27mmER2021mm31mmER2526mm35mmER3233mm40mmER4041mm46mm All sets include wooden standTypeDescriptionsModel No.ER1610pcs set includes 1/32", 1/16", 3/32", 1/8", 3/16", 7/32", 1/4", 5/16", 11/32", 3/8"204-1630ER167pcs set include:1/8", 3/16", 7/32", 1/4", 5/16", 11/32", 3/8"204-1637ER2012pcs set includes 1/16", 3/32", 1/8", 3/16", 7/32", 1/4", 5/16", 11/32", 3/8", 13/32", 7/16", 1/2"204-2040ER2010pcs set include 1/8", 3/16", 7/32", 1/4", 5/16", 11/32", 3/8", 13/32", 7/16", 1/2"204-2050ER2515pcs set includes 1/16", 3/32", 1/8", 3/16",7/32", 1/4", 5/16", 11/32", 3/8", 13/32", 7/16", 1/2", 17/32", 9/16", 5/8"204-2552ER2512pcs set include 1/8", 3/16", 7/32", 1/4", 5/16", 11/32", 3/8", 13/32", 7/16", 1/2", 17/32", 9/16"204-3260ER3218pcs set includes 3/32",1/8",3/16",7/32",1/4",5/16",11/32",3/8",13/32",7/16",1/2", 17/32",9/16",5/8",21/32",11/16",23/32",3/4"204-3261ER3211pcs set include 1/8",3/16",1/4",5/16",3/8",13/32",7/16",9/16",5/8",11/16",3/4"204-4000ER4023pcs/set with wooden stand includes:1/8",3/16",7/32",1/4",5/16",11/32",3/8",13/32",7/16",1/2",17/32",9/16", 5/8",21/32",11/16",3/4",25/32",13/16",27/32",7/8",15/16",31/32",1"204-4075