Consists of locomotive decoder and high-efficiency motor as well as installation hardware for converting most Märklin H0 locomotives with drum commutator motors to the current high-efficiency propulsion system. The electronic circuit has a total of 4 controllable functions. The "function" output is intended for the locomotive's headlights. The "f1" and "f2" outputs can be used for other functions such as Telex couplers or a smoke unit. The "f4" function allows you to turn the controlled motor functions off for easier switching of cars. The "f1", "f2" and "f4" functions can be controlled only with the Control Unit (6021), a Control 80 f locomotive controller connected to this central unit, or the Interface. The electronic circuit in this set allows you to adjust maximum speed as well as acceleration and braking delay. Controlled motor functions under different load conditions such as on ascending and descending grades. Can be coded for 80 different locomotive addresses. The "function" and "f1" functions are turned on when the locomotive is operated conventionally with AC power. Decoder dimensions 36 x 21 x 9 mm / 1-3/8" x 13/16" x 3/8".