The German 3.7 cm Pak was a iniquitous anti-tank gun in the first half of the war. After the Germans faced the T-34 and KV-1 tanks in the summer of 1941 it was nicknamed Panzeranklopfgerät or Tank Knocking Device due to its inability to penetrate their armour. However, this penetration table shows that the gun was a tad more potent than its reputation suggests.
