AB 500-3A
The AB 500-3A (Abwurfbehälter) was a cluster bomb used by the Luftwaffe during World War II. Design. AB 500-3A. The AB 500-3A was a cluster bomb container which held four bombs together horizontally. In the center of the container, there was a horizontal beam that attached to the aircraft and this beam had crutch pads at both ends to help balance the bombs. In the center of the beam, there was an adjustable circular metallic band that was divided into two U-shaped sections. The band had tensioner screws which could be used to  adjust the diameter of the band and saddle-shaped wooden shims were used to seat the bombs securely within the band. There was a vertical bulkhead which ran through the center of the beam and the adjustable band which housed a rectangular compartment that housed the cables needed for arming the Rheinmetall electric fuzes used by the German SD series of bombs. Near the front of the container, there was also a post which looked two inverted Y's that was used to arm the mechanical fuzes of French bombs which could also be dispensed from the container. When the  container was released an electric delay fuze was triggered and after the container had cleared the aircraft the tension on the belt was released and the fuzes on the bombs were armed. The bombs separated as they fell giving a tighter pattern than by dropping the bombs in a stick. Four different bomb configurations were possible: German bombs. The SD (Sprengbombe Dickwandig) or "thick walled explosive bomb" in English was a German fragmentation bomb used by the Luftwaffe during World War II. The number in the bombs designation corresponded to the approximate weight of the bomb in kilograms. French bombs . The German's captured large amounts of ordnance after the Fall of France and put these to use. The exact models of the French-made bombs mentioned in "TM 9-1985-2, German Explosive Ordnance" for the AB 500-3A are not known and there were no German designations given or diagrams of the bombs either. However, the German naming standard for captured ordnance tended to be based on what the closest German equivalent was plus FRZ to denote that it was a French bomb which would make the bombs SD 50 FRZ and SD 100 FRZ. It is possible  to narrow down the models of French bombs used from "TM 9-1985-6, French and Italian Explosive Ordnance" because not all of the 50kg and 100kg bombs were nose fuzed and the AB 500-3A had an arming system for mechanical nose fuzes.