Diablo, 138”, Self Feed Bit, 2Cutter Design Aggressive Low Thread Count Feed Screw Deliver Up To 2X More Holes Per Charge, Replaceable Feed Screw Features Pull Out Stop Mechanism That Prevents Screw From Slipping Out When Bit Is Removed From Material, Precision Heat Forged 2Cutter Head Made From Premium Steel Delivers Quality Consistency For Smooth Drilling, Up To 2X Longer Life 2X More Holes Per Battery Charge