The Montana Brand 4-in-1 Drill & Driver provides versatility and ease-of-use for do-it-yourself tasks and professional construction projects. Drill, countersink or counter-bore, then release the locking collar, flip the modular insert and drive the screw. Get jobs done easier, faster and with professional results. Sized for common #10 screws. 1/8" pilot drill with 3/8" countersink and 1/4" hex drive with #2PH driver bit. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.