ITEM NAME:Er11-A 1/4 Inch(6.35Mm)Spring Collet Seat Motor Shaft Shank Extension Rod S8X3 Er11-A 1/4 Inch(6.35Mm)Spring Collet Seat Motor Shaft Shank Extension Rod S8X3 Built in self-Release design and tools will never get stuck in holder. Use with any standard ER collet chucks for coolant-thru tool applications. Each collet is well packed in separate protective container with label. Hardened and precision ground.Performance stability,high accuracy.Durable in use. Widely used,boring,milling,drilling,silk attack,sculpture,CNC,and other processing. Colour:Black Material:steel Product size:35*6.35mm Package Contents: 1*Machine extension rod