From 'Tanks and other Armoured Fighting Vehicles 1900-1918' by BT White;
The Krupp-Daimler armoured anti-aircraft vehicle was an improvement over the Erhardt BAK of three years before in two important respects - first, the gun was on a rotating mounting and, second, the vehicle itself with four-wheel drive had greater mobility.
The Krupp 3.7cm L/30 anti-aircraft gun was mounted on a turntable on the lorry platform over the rear axle and was enclosed in a cylindrical turret with a curved, sloping face. Although cramped, the gun could be served by the crew from inside the turret. The main ammunition supply was, however, in racks in the side of the lorry, with external access only, so the gun could not be operated with the vehicle completely closed down.
The armour protection was 3.5mm, that around the driver's cab being arranged so that the upper part could be folded down to the driver's shoulder height when out of action.
The Daimler lorry chassis was of the type in which the rear axle was carried on a sub-frame. Transmission was by shafts to front and rear axles. The front tyres were solid rubber, the rear ones pneumatic.
A somewhat similar Krupp-Daimler vehicle was built in 1910, but this was unarmoured, because, following the 1909 manoeuvres in which the first Krupp-Daimler BAK and other armoured vehicles took part, it was decided that armoured cars had only limited uses in special situations
These were wartime propaganda carts, showing the French public the horrible weapons of their frightful neighbours outre-Rhin - with pictures of various prototypes taken on weapons shows long before the war.
As MZ says, German but a French postcard - I have (well, had - sold it on ebay last week) one from the same series but showing a British 60 pounder field gun
