This is an example of a Browning designed M1917A1 pattern water cooled medium machine gun. This example was assembled/manufactured by using a set of surplus machine gun parts (probably Argentinean) that were assembled onto a new manufactured machine gun receiver produced by Charles Erb. This is a full size, fully automatic, water cooled machine gun. The right side of the receiver is marked "No. USN 7775 U.S. INSP/BROWNING MACHINE GUN/U.S. CAL .30 M1917A1/MANFD BY ROCK ISLAND ARSENAL" and towards the rear of the receiver on the very lower edge it is marked "CHARLES E. ERB FREDERICKTOWN PA. M-1919-17-37 Cal .30 USN 7775". It has the functional, green painted, full length, brass water cooling jacket, and a fully adjustable rear sight graduated to 2,700 yards. This excellent machine gun is complete with an original 1917 tripod, original cradle with integral T&E mechanism and a rubber water hose contained in a tan canvas pouch. This model was the US equivalent of the German and British Maxim machine guns used towards the end of WWI and certainly throughout the post-war years and in the early days of WWII.