This is a vintage Märklin accessory, model number 7215, known as a "Tonauslöser" (Sound Trigger or Alarm Release). It is designed for use with Märklin H0 gauge (AC/Alternating Current) analog model railway layouts, and was typically used to remotely trigger the "Signalhorn" (signal horn/beeper) sound effect, often installed in locomotives (Märklin 7213/7214).

The device is a blue metal box with a red push-button and connecting wires (red, yellow, brown, black). The box features a label with the Märklin logo and the number 7215.

The original light blue box is included, showing the item number, "MÄRKLIN," and the descriptions in German ("TONAUSLÖSER") and French ("DECLANCHEUER DU SON"). The box end flap indicates it was "MADE IN WESTERN GERMANY," which dates it to the period before German reunification (pre-1990), likely from the 1960s or 1970s, based on its style and known production era for this accessory.

Condition: Used, vintage condition. The unit appears complete with original wires, and the box is present but shows wear, marks, and age-related damage. The metal base of the unit shows some surface rust/patina. Functionality is untested.