INPANOLS 23 Pcs ER40 Collet Set, 1/8-1 Precision Spring ER40 Shank Chuck fo

  

INPANOLS 23 Pcs ER40 Collet Set, 1/8"-1" Precision Spring ER40 Shank Chuck for Boring, Drilling, Tapping, Milling Lathe Engraving Tool. ECCENTRIC DESIGN: The inside of the ER40 collet nut is intentionally designed like off-centering to help mount the ER40 collet much easier.