Retrofit kit with digital decoder and high-performance motor (tuning kit). Fits most Märklin H0 locomotives with drum commutator motors. The decoder features 80 programmable addresses, automatic switching of operating modes, closed-loop control, and a digitally switchable connection for lighting that depends on the direction of travel. The acceleration and braking delay can be controlled with the control unit or Märklin Digital. The motor includes a 5-pole armature, a strong permanent magnetic field, and a pre-assembled end plate.