The weapon itself is just massive being almost 7 feet long. The Rheinmetall company was the original designer/ developer of this weapons in the early to mid 1930s. However due to the terms of the Versailles Treaty. Germany could not manufacture these weapons and so used the Solothurn factory in Switzerland to secretly manufacture them under their secret rearmament program. These were produced in 1939-1942 time frame. Eventually the Germans began to manufacture these weapons when they used them very effectively during WWII on both fighter aircraft and mounted on wheeled carriages. They were intended to be used as a light anti-tank gun, however as tank armor improved, their role shifted for use against light armored trucks and vehicles and fixed field guns. These weapons were beautifully machined and manufactured with all forged parts, that were 100% machined and fitted to exacting tolerances. They have an all blued metal finish with the complete bolt assembly left in the white. This specific weapon is rare as it still has its permanently mounted scope/sighting device mounted on the left side of the receiver. The telescopic sight assembly has a fully machined housing assembly that is actually integral with the receiver, directly over the opening for the box magazine with the optics fitted inside. It has a massive fully machined sunshade and rear eye piece with the rubber eye cup on the back. The scope itself appears to be approximately 3X and it has a single European style single aiming post for a reticle that has windage graduations on each side of the post. The top of the scope is set up just like a sniper rifle in that the elevation knob is calibrated from 1-12 (100-1200) meters, obviously for the standard 20mm cannon ammunition. In addition to the optical scope it has the standard folding front sight directly over the chamber area of the gun with a standard military style tangent rear sight, graduated from 2-15 (200-1500) meters. This weapon has the following receiver markings: 'SWITZERLAND/S18-1000/1940/No.1502". The receiver flat directly at the rear of the chamber area has a small "Cross/M" proofmark. The weapon functions in a barrel recoiling/blow-back operated fashion with the large box magazines mounted on the left side of the receiver with the ejection port on the right side. This cannon is fitted with a bipod mounted on the front of the receiver with a single adjustable monopod on the rear. It is complete with 10 original Swiss/Solothurn box magazines, two canvas box magazine carrier with shoulder straps, a large canvas bag that contains a complete cleaning rod set with four sections and handle assembly, asbestos gloves for holding on to the barrel when carrying or moving the cannon after firing, two spare recoil springs, four small tin boxes that are full of various small spare parts (cross and takedown pins and spring and washer assemblies) a armors/field maintenance cleaning or repair kit with various tools to service the cannon, a field maintenance manual, original large green painted storage box, with 42 (live) rounds of Blue tip ammunition and 30 (live) rounds of Brown tip WWII German 20mm ammunition. Most of the German ammunition is head stamped with "31 P" or "40 P" over "STAR/WaA720" with all having a brown tip stamped "40/10/WaA732".