Marklin mLD LocomotiveDecoder. Gauge: H0. This decoder is for converting Marklin/Trix H0 locomotives with built-in high-efficiency motors or other DC motors. The marklin mLD LocomotiveDecoder has a 21-pin connector and an accompanying connector circuit board for converting analog and digital locomotives. The marklin mLD LocomotiveDecoder supports the digital formats mfx, MM1, MM2, and DCC.