1) Made of high quality spring steel 2) Powerful clamping ability with high precision and stability 1) Made of high quality spring steel2) Powerful clamping ability with high precision and stability3) Used for drilling, boring, milling, tapping, engraving operation. etc4) Adapted for DIN6499B JJ-00050 DIN6343 clamping collet DIN6343-F17.5