Highly effective, battery-operated ultrasonic device with a super-slim design. Ultrasonic waves in the frequency range of animal fear and warning cries signal the marten a high danger, thus deterring it from entering the engine compartment. By varying the tone frequency (pulsating sine wave), habituation effects are prevented. The battery operation makes the device completely independent of the vehicle's electrical system. The extremely low power consumption allows for a runtime of two years with two standard 3V button cells. Additionally, the use of batteries reduces the installation time of the device to just a few minutes, as it does not need to be wired. The new, high-quality piezo disc speakers achieve an effective sound emission angle of over 170°. A blinking LED light indicates operation and further irritates the marten. Water and dust resistant according to IP 65. Universally applicable, for example, in carports, homes, or boats. Ideal for long-term parking situations such as classic cars, motorhomes, used car lots, etc.