The 7.5mm Panzerjägerkanone 40 was the most important anti-tank gun of the Second World War, as it was 1) the most-produced anti-tank gun, 2) was responsible for the destruction of most Allied tanks, 3) was the backbone of AT defences from 1943 onward, and 4) was introduced as early as 1942 in small numbers. According to Hahn, 23,000 of these were produced, but another source claims that that the number is too high and is more likely to be around ~20,000.