The Kreg Jig HD Drill Bit was made specifically for Kreg Joinery and exclusive use with the Kreg Jig HD. It features a 1/4" (6.35mm) hex shank, Kreg Quick Change Chuck compatibility, and drills a 1/2" (12.7mm) diameter pocket hole.
The 1/2" hole makes for a 50% stronger joint, allowing for the 14g screws.