This is a special circuit board with two red LEDs for the new generation of commuter cars in the Märklin H0 program (car length 28.2 cm / 11-1/8"). 2 permanently attached connecting wires.

A 73400 or 73401 interior lighting kit, or a 73404, 73405, or 73406 pickup shoe, depending on the car type, is required for connecting up the 73409 marker light kit.