7 pcs ER11 collets (1/16", 3/32", 1/8", 5/32" 3/16", 7/32" 1/4). 15pcs ER11 collets (1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 1/8", 1/4"). Collet chuck sets for CNC milling machine tools and workholding engraving machines!