Abstract: Disclosed herein is apparatus for installation on railroad cars and automatically connecting pneumatic and/or electric lines of two adjacent railroad cars. The principle of the product design is to apply pneumatic system's own pressure for automatically sealing the juncture area of the coupling and for sealing the hose end and maintaining air pressure at the compressor source when a train brake-in-two occurs. The preferred embodiment includes a substantially rectangular front-mating assembly attached to the front end of a rearwardly extending coupler shank and an installation portion for attaching said rectangular front-mating assembly to the undercarriage of a rail-car via said coupler shank. Said front-mating assembly includes a male and a female mating heads mounted on its front panel and a pair of alignment members installed at its two sides for guiding said mating heads to the appropriate coupling positions during the coupling.