Retrofit kit with controlled digital decoder and high-performance motor (Tuning Kit). Fits most Märklin H0 locomotives with a drum commutator motor. The decoder features 80 programmable addresses, automatic switching of the operating mode, closed loop control, and a digitally switchable connection for lighting that depends on the direction of travel. Starting and braking delay can be controlled with the Control Unit or Märklin Digital. The motor includes a 5-pole armature, a strong permanent magnet field, and a preassembled end shield.