The ZB-30 and ZB-30J were Czechoslovakian light machine guns that saw extensive use during World War II.

However, the ZB-30 had some design differences, making it similar to the later ZGB-33, which was an early prototype of the Bren gun.

[6] Like the ZB-26, the Wehrmacht adopted the ZB-30 after the occupation of Czechoslovakia, renaming it the MG30(t); it was used in the same role as the MG34, as a light machine gun.

In the opening phases of World War II, the ZB-30 in 7.92 mm Mauser caliber was used in large numbers by elements of the German Waffen-SS, who did not initially have full access to standard Wehrmacht supply channels.

[1] Comparison of original ZB vz.26 and modifications: Note - The ZB 30J was a late design iteration of the ZB 30 for sale to Yugoslavia (originally spelled with a J) that featured an adjustable gas system so that commonly available light and heavy 7.92mm ball ammunition would cycle the mechanism.