Cabinets for loudspeakers; Global positioning system (GPS) consisting of computers, computer software, transmitters, receivers, and network interface devices; Headphones; Metal detectors; Microphones; Sunglasses; Time recording apparatus; Tool measuring instruments; Video baby monitors; Diagnostic apparatus for testing food; Graduated rulers; Optical fibers; Portable electronic recorder for measuring and recording multiple voltage, current and thermocouple readings from various transducers; T...