/ Metal locomotive frame.
c Digital locomotives with high-efficiency propulsion. Maximum speed and acceleration / delay are adjustable. Special motor with electronically enhanced load compensation or a compact bellshaped armature. Can be operated with Märklin transformers, in the Märklin Delta system or in the Märklin Digital system. One controllable auxiliary function (function), when the locomotive is being run in the Digital system.
d Digital decoder with additional, digitally controlled functions (f1, f2, f3 or f4) when operated with the 6021 Control Unit. The functions present depend on how the locomotive is equipped. Standard function (function) active during conventional operation.
h Built-in sound effects circuit.
H Triple headlights that change over with the direction of travel.
j Built-in interior details.
V Locomotive / car has sprung buffers.
W Automatic claw couplers can be replaced with reproduction prototype couplers.
4 Era 4