13899 Features: -Self Feed Bits.-For drill provides clear cutting without effort.-Drill cuts faster and amp, has improved balance with Reduced run out.-Shanks have flat surfaces for secure chuck grip.-Feed screws removable and amp, replaceable.-Feed screw provides past, effortless feeding even in gummy wood.-Double sided feed.-Screw and amp, allen wrench furnished with each bit - after bit is worn, you can reverse the bit to the other side.-Inside cutting plane shaves Hole radius for clean, smooth holes without pressure.-Spurs on outside diameter cut holes clearly and amp, accurately.-Universal 0.44" shank.-Size: screw point replacement. Warranty: -1 Year warranty.