 It was produced by Mauser and Rheinmetall-Borsig from 1935.The KwK 30 also served as the basis for the 20 mm C/30, an aircraft variant that was mounted experimentally in some Heinkel He 112 fighters and proved to make an excellent ground-attack weapon during the Spanish Civil War.Direct ground-attack was not considered a priority for the Luftwaffe and the cannon was not used on other designs.