37 Installation, maintenance and repair of low voltage security systems for commercial buildings; installation, maintenance and repair of low voltage telecommunication systems comprising telecommunications networking transceivers, distribution signal amplifiers for video signals, wireless radios, and data cables therefor; installation, maintenance and repair of closed circuit TV security and surveillance systems comprised of cameras, electronic switchers for audio and video signals, monitors, microphones, and audio and video recorders; installation, maintenance and repair of burglary systems comprised of door alarm sensors, motion sensors, electronic glass break sensors, infrared detection apparatuses for monitoring outdoor perimeters of buildings, electronic card readers, electronic programmable keypads, electronic controllers for controlling access to building premises, burglar alarms, fire alarms, audio and audio/video intercoms, and fiber optic cables, connectors and couplings for fiber optic communications networks; installation, maintenance and repair of public address (PA) and paging systems comprised of speakers, amplifiers, and microphones; installation, maintenance and repair of smoke and gas alarms; installation, maintenance and repair of video surveillance systems comprising cameras, electrical switches, electronic motion sensitive switches, monitors, microphones, and recorders; installation, maintenance and repair of tele-video communication systems comprising telecommunication and video networking transceivers and distribution signal amplifiers for video signals; Installation of theft prevention devices; Fire alarm installation and repair