repair and servicing of electrical and electronic apparatus and instruments for use by businesses, educational and professional concerns; namely, audio conferencing equipment comprised of headphones, wire and wireless microphones, audio transmitters and multi channel audio receivers, and accessories therefor; unrecorded and pre-recorded audio and video tape, audio cassette tape duplicators and accessories therefor, digital and analog audio tape recorders and players and accessories therefor, compact disc players and accessories therefor, audio tape editors and accessories therefor, digital audio tape processors and accessories therefor, digital master recorders and accessories therefor, microphones and accessories therefor, audio mixers and accessories therefor, audio consoles and accessories therefor, multiple video cassette playback systems and accessories therefor, video multiple cassette recorders and accessories therefor, video tape recorders and players and accessories therefor, video cameras and accessories therefor, video monitors and accessories therefor, television monitors and accessories therefor, satellite conferencing systems comprised of receivers, signal converters, programmable site controllers and accessories therefor; video conferencing systems comprised of video monitors, video cameras, video controllers, cabinets, microphones and accessories therefor; computer CRT screens and accessories therefor, video projectors and accessories therefor, large screen video display units and accessories therefor; language laboratory systems consisting of tape recorders and players, receivers, video monitors, headphones, language modules and accessories therefor; CD-ROM recorders and players, CD-ROM diskettes, CD-ROM computers, CD-ROM software, videodisc players, touch screen video monitors; computers, comuter peripherals, accessories and operating software therefor; computer software used for videography, video production equipment; namely, signal processors, editors, switchers and switcher/special effects generators and accessories therefor; security systems; namely, video cameras and lenses therefor, video monitors, video printers, video camera housings, camcorders, sequential switchers, time lapse videorecorders, videorecorders, peripheral components and accessories therefor; video tape duplicators, automatic changers for removing a prerecorded video cassette from a video cassette duplicator and inserting an unrecorded video cassette, digital video recorders, rewritable and recordable optical discs, prerecorded optical discs, optical disc recorders and players, pre-recorded video discs, downconverters, frame recorders; electronic medical equipment; namely, video printers, video cameras, digital video recorders and players, analog video recorders and players, video still image recorders and players, video monitors, video processors; electronic photography and publishing equipment; namely, video printers, video scanners, information handlers, still video camera recorders, still video players, still video recorders/players, and accessories therefor; computer workstations and peripherals; data storage equipment; namely, magnetic floppy disks, magnetic floppy disk drives, computer hard drives; imaging devices; namely, industrial video cameras and accessories therefor; magnetic devices; namely, magnetic tape readers and tape heads; semiconductors