High-voltage impulses ranging from 300 to 700 V are delivered through 6 high-voltage plates, each measuring 4 x 4 cm, nickel-plated, distributed along two 350 cm long cables, in combination with ultra-high whistle tones. The plates are placed in vulnerable areas of the engine compartment. A piezoelectric sound transducer operates at a frequency of 12 kHz in intervals of 22 seconds. Martens avoid this frequency range. Humans and pets are not affected. Pre-wired and ready for installation.