Avanti Pro, 4 piece glass and tile drill bit set. Set consists of 1 each 1/8", 3/16", 1/4" and 5/16" glass and tile drill bits. Avanti Pro glass and tile drill bits provide top quality performance when drilling into glass and tile. This range features a rapid start tip that delivers fast starts, with no walking. A carbide tipped cutting edge extends the life of the bit, allowing users to drill more holes. The 3-flat shank delivers added stability. Avanti Pro glass and tile drill bits are only for use with drills in rotary mode.