ITEM NAME:New 12Pcs ER16 Spring Collet Set For CNC Milling Lathe Tool Engraving Machin Hn.Model: ER16. 12 x ER16 Collets. Use with any standard ER collet chucks for coolant-thru tool applications. Suitable For: Boring, milling, drilling, tapping, engraving, CNC, spindle machines, and other processing.