Polish armoured cars in 1939 were used in eleven armoured car squadrons of Armoured Detachments (Dywizjon Pancerny, battalion-size), assigned to Cavalry Brigades as their reconnaissance element. Each squadron had seven cars (two platoons and a commander).*
The detachment also had a tankette squadron and a commander's armoured car. *
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A basic car type was light wz. 34 armoured car, used in ten detachments. *
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Only the 11th Armoured Detachment of Mazovia Cavalry Brigade (Mazowiecka Brygada Kawalerii) was equipped with heavier wz. 29 Ursus armoured cars. They were armed with low-velocity 37 mm SA.18 gun and 7.92mm MG in a turret (mounted in different sides, though), and 7.92mm MG in a rear plate.* 
The combat record of those few obsolete machines was surprisingly successful, and they destroyed at least 7 enemy AFVs. *
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_____________[description by PIBWL]*