From the Manufacturer
The Kreg Quick Change Pocket-Hole Kit is the most complete quick change system designed specifically for use with Pocket-Screw Joinery.
This one simple kit provides everything you need to switch from drilling pocket holes to driving pocket screws in just seconds. The kit includes the new 3/8″ diameter step drill bit with 1/4″ hex shank that snaps directly into the quick-change chuck with no need for an adaptor, a Quick-Change chuck designed to eliminate slippage and optimize drilling power, an allen wrench, a depth collar, and a 6″ long, #2 square drive bit for pocket screw applications.