This compact set Step Drill Bits which includes one 4-12mm, one 4-20mm, and one 3-12mm. Two-fluted design can provide faster, smoother cutting.Note:Before starting drilling and screwing, the Automatic Center Punch can be used to mark hole locations. It delivers an automatic, high-impact, spring-loaded strike when pressed against wood, metal, and plastic surfaces.An adjustable cap regulates striking force. It features a heat-treated alloy steel punch with a sharp precision tip and a corrosion-resistant brass body with non-slip knurled grip. 4 cutters come in the following sizes:5 step drill bit: 4-12mm (4mm, 6mm, 8mm, 10mm, 12mm)9 step drill bit: 4-20mm (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm)10 step drill bit: 3-12mm (3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm)11 Step drill bit:3-13mm (3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm ) Automatic Center PunchBefore starting drilling and screwing, the Automatic Center Punch can be used to mark hole locations. It delivers an automatic, high-impact, spring-loaded strike when pressed against wood, metal, and plastic surfaces. An adjustable cap regulates striking force. It features a heat-treated alloy steel punch with a sharp precision tip and a corrosion-resistant brass body with non-slip knurled grip.Colour: goldMaterial:High speed steelPackage Contents:1*3-12mm Drilling Bit1*4-12mm Drilling Bit1*4-20mm Drilling Bit1*3-13mm Drilling Bit1*Center punchOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.