5 piece multi purpose drill bit set, consists of one each 1/8", 3/16", 1/4", 5/16" and 3/8", for rotary or percussion drilling, cobalt and tungsten carbide tip for maximum hardness and resistance to heat and wear, for use with masonry, concrete, brick, marble, granite, hardened steel, cast metal, fiberglass, plexiglass, ceramic tile, hard wood, soft wood and glass, plastic case.