24 sizes individual drill bits in 3: This set includes three standard step drill bits that replace 28 individual drill bits, comes with one 4 to 12mm five-step bit, one 4 to 20mm nine-step bit, 3 to 12mm ten-step bit. Strong durability: HSS + titanium durability. Avoiding the inconvenience of a -flat to a firm grip. Easy drilling: Two-fluted design provides faster, smoother cutting. Provided with small pressure and the sets can cut through wood, sheet metal, steel and other surfaces. Automatic center punch: Delivers an automatic, high-impact, spring-loaded strike when pressed against surface, adjustable cap regulates striking force. Wide usages: Mark hole locations and start drill bits and screws, preventing wandering, heat treated alloy steel punch with sharp precision tip, corrosion-resistant brass body with non- knurled grip. This compact set replaces 24 individual drill bits in 3pc Step Drill Bits which includes one 4-12mm, one 4-20mm, 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- knurled grip. The 3 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) Color:gold Package Contents: 3 x Metric Step Drill Bit 1 x Auto Center Punch Only the above package content, other products are not included. Note: Light shooting 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.