4-Cutter Tip Prevents Seizing While Drilling In Reinforced Concrete. Reinforced Crushing Tips Minimize Vibration And Protects Carbide From Breakage.SDS Plus Sonic Masonry Drill Bit. Sds Plus 4-Cutter Drill Bit 3/16" Cutting Length 6" Overall Length 18" Self-Centering Crushing Point For Accurate Drilling.