The adapter ring and thread allow you to tighten screws to the set depth.
A strong internal magnet holds the bit and screw properly when screwing.
An additional magnet on the ring makes it easier to screw in screws in hard-to-reach places and prevents quick wear of the tip.
The 1/4" (6.35 mm) chuck allows you to use most screwdrivers and drill drivers available on the market.