This is a beautiful example of a super rare, original "tool room sample" of the 1918 Mark I Pedersen device as intended for use on the Model 1903 Springfield rifle. These device and the Mark I rifles have always been a very scarce and highly desirable item for the 1903 Rifle collector and certainly any U.S. Martial arms rifle collector. This item and the entire concept was the brain child of J. D. Pedersen a engineer and inventor of the Remington firearms company, who is also credited with developing several innovative firearms, such as a pump action shotgun and semi-automatic pistol during this time frame. As we all know the concept was that with this device was developed to be inserted into a standard Mark I Model 1903 bolt action rifle, that would immediately convert that rifle into a semi-automatic rifle capable of sustained semi-automatic fire using the standard 40 round magazine, very innovative for 1917 when every country was still using bolt action rifles. This device was demonstrated to Gen Crozier, Chief of the U.S. Ordnance Dept and other representatives of the War Dept. in 1917. They immediately saw the technological/battle field advantage this item would mean to the US Military and immediately classified the program and all subsequent manufacture of these devices as secret well after WWI. An initial order was placed for 100,000 of these items along with the modified Mark I rifles. The production items were all manufactured by Springfield Armory and subsequently stored there until a sufficient quantity were on hand so they could all be issued at once to specific units in France. The idea was to capitalize on the technology advantage and surprise the Germans in some future engagement. However the war ended before they could be issued and all items were subsequently destroyed after WWI, making these extremely scarce and rare today, with this specific example is even more rare in that it is one of the ultra-rare Remington Arms produced "tool room" or early prototype samples that were made specifically for demonstration to the U.S. Government. These are easily identified because they were made prior to Mr. Pedersen filing for his various patents on these devices. Consequently the markings on this rare device are located on each side of the sliding bolt assembly/top cover and are "U.S.A. 1918-MARK I and REMINGTON-BRIDGEPORT", versus the later production versions that included the additional "Patent Applied" for markings and a serial number for the actual device.