Powers™ Depth Control Bit, Drill Stop, series: Accu-Bit™, 3/8 in Bolt, For Use with: 1/4 in Mini Drop-In anchor, 7/8 in Drill, Carbide. DeWALT® 00392 Accu-Bit™ Drill Stop Depth Control Bit, 3/8 in Bolt, Use with 1/4 in Mini Drop-In Anchor