Couplers are transformer based devices which connect various terminals/subsystems to the data bus via the couplers stub ports. The coupler also provides protection of the main data bus from the occurance of an electrical short on a stub. The type of coupler (# of stubs) and selection of package style are application dependent.These couplers are typically used in simulation, test and vehicle applications where quick connection to a MIL-STD-1553 Bus is required.Flange mounted couplers are so called because they attach to a mounting surface using the holes supplied on the couplers flanges, as shown in the photographs above.