The TK (TK-3) and TKS were Polish tankettes developed during the 1930s and used in the Second World War.
575 TK/TKS tankettes formed the bulk of the Polish armoured forces before the outbreak of war. They suffered heavy losses during the invasion of Poland, often being the only armoured fighting vehicles available. Their small size suited them for reconnaissance and infantry support, but with their light armament of a single machine gun they stood no chance in combat against German tanks, except against the Panzer I.
After the conquest of Poland, captured tankettes were used by the German army in various support roles, mostly for training, security duties or as artillery tractors. Many captured tankettes were also used by the Luftwaffe for airfield security and snowplowing. Some were later sold to the puppet state of Croatia. In spring 1941, the National Police received 18 TK-3 tankettes, some with the 20mm gun, while in summer 1941 the Army received 18 TKS, 4 of them being sent to the Ustashe Militia.