The tool has two flat head screw driver blades to remove the screws from your lock. The threaded end was used to store your tow worm and also to push the barrel pins out of the stock of the musket. This tool was used during the 18th century by the military. You can see one of these in The Encyclopedia of the American Revolution. This one is reproduced from an original musket tool. The tool stores nicely in your shooting pouch or haversack. The overall measurements are 5" long x 4 3/4" wide.