Universal circuit board with several LEDs, which will fit in most of the passenger cars in the Märklin H0 program. One 73400 is required for a short car (example: Langenschwalbach cars); for long cars (example: UIC-x at 28.2 cm / 11-1/8" length) two 73400 are required. The circuit boards can be plugged together in a series or they can be shortened. Mounting hardware is included. The separate 73404, 73405 or 73406 pickup shoe / ground spring power feed set, or the 72020 current-conducting coupler with the 72050 ground spring is required, depending on the car type.

The 73400 lighting kit (soft light for older eras) and the 73401 lighting kit (white light for modern cars) have technically interchangeable parts.

A 73404, 73405 or 73406 pickup shoe / ground spring power feed set, or the 72020 current-conducting coupler with the 72050 ground spring is required for the 73400 lighting kit.