This is ER20 High Quality Collet with 2.5mm Hole.
Specifications:
  • Made from Alloy spring steel and fully hardened.
  • All critical collet surfaces are precision ground for accurate fit.
  • Works in all ER20 Collet Chucks.
  • ER16 collet has a full 2.5mm range of collapse while maintaining full accuracy.
  • ER16 collet has a range : 2.0mm to 2.5mm.