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. Kit contains: 4-6-8x7/8" (50pcs.), PHS SMS(50pcs.), and a 3/16" Drill Bit