SHINA New 6pcs 3/16 11/32 1/4 7/16 17/32 5/8 ER25 Spring collet CNC Cilling Lathe Made of high grade specially formulated spring steel. Hardened and precision ground. Built in self-Release design and tools will never get stuck in holder. Clamping range :0.005" Accuracy : 0.0005mm