Field-glasses; Radios; Walkie-talkies; Webcams; Access control and alarm monitoring systems; Bicycle speedometers; Burglar alarms; Closed circuit TV systems for security and surveillance, namely, cameras, switchers, monitors, microphones, and recorders; Electronic access control systems for interlocking doors; Frequency converters; Infrared cameras; Infrared detectors; Internet digital video recorders; Portable handheld electronic digital video messengers for recording, storage, transmission ...