Misc Vendor HC+12MM Glass Drill Bit, Nemo Power Tools, Type HC 12mmNemo Glass Drill Bit, HC 12mm Nemo Glass Drill Bits are used for smoother operations for under water work. These drill bits require less force and can drill into hard rocks/concrete without applying high counter pressure. This helps drilling under water when applying forward force to the drill again the surface is difficult. Glass and tile drill bits provide smooth, accurate drilling in concrete, ceramic tile, marble, china, mirrors and glass Precision tip solves bit wander and bit walking High-quality with reinforced head prevents bit cracking Innovative geometry allows bit to drill faster