This little set is designed as a drop-fit to replace the plastic machine gun barrels on any Italian 1/48 scale aircraft kit that was armed with the Breda 12.7mm machine guns.
Master Model provides a pair of gun barrels, each comprised of 2 pieces: a perforated jacket and the gun barrel itself. The brass is extremely cleanly cast, with full perforations in the jackets and a nice open muzzle on the barrels themselves. No cleanup of these parts will be required. The brief instructions show the barrels are to be inserted into the jackets, then placed onto the model in the appropriate location.