electronic components, more specifically piezo-electronic buzzers

SCIENTIFIC, NAUTICAL, SURVEYING AND ELECTRICAL APPARATUS AND INSTRUMEN TS (INCLUDING WIRELESS), TELEPHONE SETS ANDTELEPHONE EXCHANGES, PHOTO GRAPHIC, CINEMATOGRAPHIC, OPTICAL, WEIGHING, MEASURING, SIGNALLING, CHECKING (SUPER-VISION), LIFE-SAVING AND TEACHINGAPPARATUS AND INSTRU MENTS; COIN OR COUNTER FREED APPARATUS+ TALKING MACHINES; CASH REGISTE RS; CALCULATING MACHINES; FIRE-EXTINGUISHING APPARATUS; INCLUDING PIEZO-CERAMICAL BUZZERS AND ELECTRONIC AUDIBLE SYSTEMS

Ultrasonic Transmitters for Driving Away Rodents