The Bondhus 4mm Weighted T Hex Key HUGE upgrade from the stock “L” hex wrench that comes with the Nova chuck kits. The handle is weighted, so you can start the screw, spin the hex portion between your thumb and forefingers to quickly spin the screw in our out, the just lock with the T-handle. This will probably halve the time you spend changing jaws. This is NOT the ball hex, which you don’t want for jaw changes – it locks rigidly into the jaw screws and holds in an upright position.