Although most Polish weapons were foreign types manufactured under licence, there were some local designs. Three wz. 36 46mm infantry mortars were deployed in each infantry company. Number 1 without the base plate is the standard wz. 36, while number 2 to the right is the original version tested in 1932-33. The Polish wz 35 anti-tank rifles were the infantry's primary means of anti-tank defence with 92 per division. Although it was similar to German anti-tank rifles used in the First World War, it pioneered the use of tungsten cored projectiles, which enabled it to penetrate the armour of nearly any of the German tanks in service in 1939. Unfortunately the ammunition was so secret that the rifles were not distributed until the September mobilisation, limiting their use. The mechanisation of two Polish cavalry brigades led to some modernisation of the field artillery. The standard French Mle. 97 75mm gun was made suitable for motorised traction by the addition of a new suspension and pneumatic tyres. This particular battery served with the 10th Mechanised Brigade. Armoured support for infantry and cavalry units was provided by the small TK and TKS tankettes. There was a company of 13 in each Infantry division and a squadron of 13 in each cavalry brigade. Here, they are seen on pre war manoeuvres with an infantry company. Poland purchased 39 Vickers 6-ton light tanks in 1931 including 16 of this model with the 47mm gun. An Improved type was licence produced in Poland as the 7TP light tank. The original Vickers, after some local modifications, was assigned to the two mechanised cavalry brigades.