A group of Milizia Volontaria per la Sicurezza Nazionale of MVSN legionnaires aboard an armored Renault ADR during a partisan clean-up operation in a Yugoslav village in 1943. Italian forces during WW2 lacked armored personnel carriers so improvised them from existing vehicles such as the captured French Renault ADR 1 1935, a 3.5 ton truck with a 4-cylinder engine with the military intended variant produced with only the 4-cylinder in-line gasoline engine delivering 62 horsepower at 2,350 rpm and a 5-speed transmission. The trucks were delivered to the Armée de Terre French Army in 400 units, 126 of which went to the Garde Républicaine ( Republican Guard) before and during the war. Almost all were requisitioned by Axis troops after the French Campaign. Given the improvised nature of these armored personnel carriers, their protection was also improvised or taken from scrap yards. The cargo bays were protected with 10 mm thick trench shields dating back to World War I. 

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Rectangular or ellipsoidal firing loopholes for infantry passengers were made into the plates and shields. These shields and plates were placed in two rows, one on top of the other, on the cargo bays, held together by welding. The final vehicles weighed around 4 tons, had a 2 man crew of Driver and vehicle commander plus passengers, one of whom may be a gunner. They had a speed of around 50 km/h and a range of around 250 km depending on the amount of armor and weaponry mounted to the vehicles. The first row was placed at 90° and consisted of eight trench shields (or plates of the same size) welded to supports fixed directly to the vehicle’s chassis. The second row was composed of eight shields or plates welded and angled at about thirty degrees. Like many other protected vehicles produced by Italy, both in an improvised and industrial manner, a major problem was the lack of a roof. This created problems with shrapnel or hand grenades falling inside the cargo bay, injuring or killing all occupants. In addition to this serious problem, the lack of a roof exposed the transported soldiers to the weather conditions.

To solve these problems, bomb nets or wooden boards were mounted on the roof to protect from bombs thrown at the vehicles. Initially, the vehicles produced received armor only on the cargo bay. Later, the vehicles also received cab protection to protect the driver and the vehicle commander. Some armor plates or trench shields were placed to protect the doors and the front of the cab by cutting a large slot for the driver and maintaining the slits on the doors and the side of the vehicle commander. Together with the cabs, the fuel tanks were also armored to increase protection, but the wheels and the engine compartment, and the radiator were never armored. In the beginning, the armament was absent on the Renault ADR Protetti vehicles. The defense was assured by the cargo bay slits, 13 on each side. Seven were in the lower row of trench shields and armor plates, and 6 in the upper row. In addition, there were six on the rear, 4 in the lower row and 2 in the upper one, for a total of 32 slits on three sides of the cargo bay.

For defense in these cases, the bipod of a light machine gun Breda Mod. 1930 was simply placed on the roof of the cabin, but it had many problems with reliability and a very slow clip reloading system that did not allow an effective suppression fire with only 20 6.5MM Mannlicher-Carcano rounds at a mere practical 150 rounds per minute and no protection for the gunner position save for a gun shield on some of the conversions.

The machine gun entered service in 1930 and 10,000 were produced until 1945. It proved unsuitable for the role of infantry support because of its weight, its mechanical unreliability and too much maintenance required to keep it effective. At the same time, the cabin of the truck was armored. As a consequence, three more rifle slits were added for the vehicle commander and driver, one on the right side, one on the left side, and a third one on the front.