Features:

Model: ER11
Precision:<0.012
Material:Spring Steel
Ground Roughness is Ra0.4 Microns, plus overall fine polish
Gripping Range: 1 mm,1.5 mm,2 mm,2.5 mm,3 mm,3.5 mm,4 mm,4.5 mm,5 mm,5.5 mm,6 mm,6.5 mm,7 mm,1/4",1/8"
Upper Diameter: 12 mm
Bottom Diameter: 8 mm
Height: 20 mm
Suitable For: Boring, milling, drilling, tapping, engraving, CNC, spindle machines, and other processing

Features:
1.Durable and practical.
2.Special angled slots increase rigidity.
3.Protects tool holder from contaminants.
4.Better overall balance of tool holder assembly.
5.Use with any standard ER collet chucks for coolant-thru tool applications.