9 Duplexers; Modems; Access control and alarm monitoring systems; Antennas; Electronic and optical communications instruments and components, namely, optical receivers; Electronic components, namely, piezoelectric switches; Electronic devices for locating and tracking lost articles, people, pets using radio frequency, global positioning systems, cellular communication networks; Radio frequency identification (RFID) credentials, namely, cards and tags, and readers for radio frequency identification credentials; Sound reproduction equipment; Voltage monitor modules; Voltage regulators