Piezoelectric sound components, namely, piezoelectric speakers

PARTS AND FITTINGS FOR ELECTRIC AND ELECTRONIC APPARATUS, NAMELY, LOUD SPEAKERS; MICROPHONES; [ CAPACITORS; VARIABLE CAPACITORS; RESISTORS; VARIABLE RESISTORS; POSITIVE TEMPERATURE-RESISTANCE COEFFICIENT THERMISTORS; NEGATIVE TEMPERATURE-RESISTANCE COEFFICIENT THERMISTORS; CERAMIC FILTERS; MICROWAVE FILTERS; PIEZOELECTRIC TUNING FORKS AND ELECTROMAGNETIC TUNING FORKS; PIEZOELECTRIC OSCILLATORS; ] PIEZO ALARM UNITS; [ RESONATORS; RC CIRCUITS; HIGH VOLTAGE MULTIPLIERS; ELECTRON MULTIPLIERS; HIG...