.25 inch, Impact Rated Rotary Masonry Bit Set, Rapid Load Provides Quick and Easy Accessory Changes Without Re-Chucking, Accessories Have A Hex Shank Locking System To Prevent Slipping, Holder Fits All Brands Of .375 inch and .5 inch Cordless and Corded Drills, For Drilling In Brick, Block, and Concrete, Carbide Tip Aggressively Penetrates Surfaces.