Double for Cross for Head Screwdriver Bit Set, alloy steel with heat treated for durability, anti-impact collar design can limit screw penetration and damage to board, more the screws and plasterboard screws locating Double end screwdriver bits for extra versatility and the screw holder collar can the screw in place to make work easily Double end screwdriver bits for extra versatility and the screw holder collar can the screw in place to make work easily Depth stop design can limit screw penetration and damage to board.Designed to be used with any power drill or cordless drill, Manufacturer: XIAOQENAN