Savannah Self-centering 4 jaw woodturning chuck has a large range of jaw adjustability. To adjust the quick action on the chuck Simply insert the locking levers into the chuck and rotate them in opposite direction to grip in the contraction mode or expansion mode. The powerful jaws will grip and expand in a 2" to 3" dovetail recess in the base of your project. The chuck body is chrome plated and the jaws are black anodized to protect against corrosion. The chuck comes with a screw chuck that does not require any accessories or disassembly to use.