Ribbed plastic anchors work with various diameter sheet metal screws. Ideal for anchoring in concrete, brick or wallboard. The anchor is corrosion resistant. A pre-drilled hole is required. Recommended for quick, easy fastening of fixtures in a variety of light duty applications. You'll find this kit useful for a variety of home and commercial applications. Includes: (50) 8-10-12 anchors, (50) Phillips sheet metal screws and (1) 5/16 In. drill bit.