The ZB-53 was a Czechoslovak machine gun. A versatile weapon, it was used both as a squad support weapon, as a mounted machine gun for tanks and other armoured vehicles, and on fixed positions inside Czechoslovak border fortifications. Adopted before World War II by the armies of Czechoslovakia (as Těžký kulomet vz. 37, heavy machine gun model 37) and Romania, it was also license-built in the United Kingdom as the Besa machine gun. Following the German invasion of Czechoslovakia, large quantities of the weapon were captured by the Wehrmacht and used during the war under the designation of MG 37(t).

The Besa machine gun was a British version of the Czechoslovak ZB-53 air-cooled, belt-fed machine gun.