Use for head bolts, brake caliper bolts, door handle screws, axle bolts and other applications. Bits to fit 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm and 18mm sizes. The three largest sizes are designed to work on tamper-proof applications. Included in a handy vinyl holder This 9 piece bit set includes the following: 6mm, 8mm, 10mm and 12mm with 1/2" hex drive, 14mm and 16mm with 5/8" hex drive, and the 18mm bit with 3/4" hex drive.