This generator produces ultrasonic sounds, which are adjustable within the range of approx. 8...35 kHz. It is said, that crawling and jumping parasites are banished through the ultrasonic sound. Frequency can be adjusted so that the domestic animal will not be disturbed. Operating voltage: 9V=. As loudspeaker is required either a small treble loudspeaker 8 Ohm (no piezo!) or a dynamic 8 Ohm earphone. (Not enclosed in the kit).