【PH2 Screwdriver】These Drywall Screwdriver Bits are made of high-strength S2 alloy steel, these screwdriver bits are very Heat treated to resist breakage and wear, impact resistant tool steel for maximum durability with a 1/4 "hex shank for use in bit holders. 【PH2 Screwdriver】These Drywall Screwdriver Bits are made of high-strength S2 alloy steel, these screwdriver bits are very Heat treated to resist breakage and wear, impact resistant tool steel for maximum durability with a 1/4 "hex shank for use in bit holders. 【Protect the surface】Depth stop design can limit screw penetration and damage to the board, easier to install drywall screws. Using these screwdriver bits, the head of the drywall screw will stretch and dimple the of the drywall, but will not break it. 【Magnetic head】These drywall bit holders are magnetic head, so they can be firmly fixed on the screw. Strong magnetic, it can easily suck the screws when using. 【Retaining Ring】The ph2 screwdriver bits have a collar that acts as a stopper, preventing the bit from following the screw head into the drywall - once the collar comes into contact with the masonry sheathing, the bit cannot continue. 【Adaptation Tools】The magnetic cross screw holders are equipped with 1/4 in. Hex shank. They are designed to fit any power drill and cordless drill for normal use., Manufacturer: Akozon