This Con-Cor MUmP54 with Trailer "Bride and Groom" Set is based on electric multiple-unit passenger equipment used in PRR's electrified territories. In the mid-1930s the Pennsylvania Railroad rebuilt a series of cars at its Altoona shops, and added a permanent trailer making a two-car semi-permanently coupled set. Nicknamed "Bride and Groom" sets, the cars differed in that they only had head-lights at one end of each car and one pantograph per set. Sets have one powered and one unpowered car; the decoder-ready powered car includes a built-in speaker for when you're ready to add sound and DCC. Optional DCC decoders can be easily added to the powered unit in the MUmP54 set by the customer if desired (decoder sold separately). A standard NMRA eight-pin interface is factory mounted in each powered model.