High Compatibility: This set includes a 4-inch diameter core drill bit, three adapters, and one pilot drill, making it compatible with most standard drills and hammer drills. Combine versatility and convenience for various tasks Precise Positioning: Our diamond dry coring bit comes with a pilot drill, no need for pre-drilling. The sharp tip quickly penetrates the surface, allowing for faster and more accurate positioning, ensuring smooth operation without switching modes Durable & Sturdy: Crafted from quality carbon steel with high-precision welding, this concrete core drill bit boasts 95HRB hardness. It resists heat buildup during high-speed drilling or dry operations, avoiding blade detachment and enhancing longevity High-Performance Drilling: Our core bits for concrete features precision-ground teeth for smooth, burr-free edges and faster, accurate cuts