One Bit Fits All: The bit comes with 12 hole sizes: 6mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm. , saving you time and effort to change bits, quadrupling your drilling efficiency. Durable Titanium Coated Drill Bits: The step drill bit is made of 4241 high speed steel, wear-resistant for better and faster drilling performance. Universal Compatibility: The fast striking tip drills twice as fast as average step drills and can drill through acrylic, PVC, wood, aluminum, and iron sheets. Easy to Use: Compared to ordinary twist drill bits. The jolt is small, and it can be opened without the use of center punching.