 Complete the following phrase:  It first saw service during the Spanish Civil War in 1936, where it performed well against the light tanks of the conflict. It was first used during the Second World War against Poland in 1939 and had little difficulty with any of the Polish tanks. The Battle of France in 1940 revealed its inadequate penetration capability against French and British heavier tanks, particularly the Char B1, and especially the Matilda II, receiving the derisive nicknames Heeresanklopfgerät army door-knocking device or PanzerAnklopfKanone tank door-knocking cannon from its crews, but it sufficed to defeat the bulk of the Allied armor in the campaign. The 