This HSK 63F Collet Chuck features an internally mounted Zeta collet nut which gives the tool holder a more efficient design and allows for high clamping power with the coated Zeta nut. You still use the standard ER or OZ type collets with this system, the only additional item is a special tool to operate the nut. The benefits are clear in design for high speed and improved collet clamping power. These are available in ER16, ER32, and SYOZ25 for the most popular HSK 63F CNC router tool holders.