1.[3-in-1 Stepped Hole Design]– This diamond drill bit features a triple-step cutting structure (20mm, 35mm, 50mm), allowing seamless hole expansion with one tool. Ideal for precision drilling in tight or varied-depth applications. 2.[Optimized for Tough Surfaces]– Engineered for durability, this core drill bit handles a range of hard materials such as tile, marble, engineered stone, quartz, granite, and concrete—making it a versatile solution for both indoor and outdoor drilling tasks. 3.[Sharp Multi-Layer Cutting Edge]– Equipped with a diamond-coated, multi-layer tip, this stone drill bit superior abrasion resistance, smooth cutting performance, and extended life, reducing wear even after multiple heavy-duty uses. 4.[Compatible with Standard Drills]– Designed for easy use, this diamond hole saw bit fits most handheld electric drills. No special tools required, making it suitable for professionals, contractors, and DIY users alike.