1Adjustable Depth: The height of the screwdriver bit is adjustable. The magnetic drill bit can fix the screws to a predetermined depth, so that drywall screws can be used accurately. 2Firm in Fixation: The strong magnetic head can fix the drill bit for easy access. Suitable for 1/4in cross bit. It can quickly and accurately drive gypsum board screws. 3Wide Application: Applicable to terrace building, gypsum board, chipboard or plywood, wood frame, plywood flooring, etc. It is very suitable for daily use indoors and outdoors. 4Durable Material: The hex shank screwdriver bot is made of chrome vanadium steel, with high hardness, rustproof, corrosion resistance, and durability. The magnetic head effectively keeps the screw straight. 5Including 2 Sets: There are 2pcs fast change bit holder in the set, as well as 2pcs cross screwdriver bit on the holder, largely facilitating your working.