Intercoms; Videophones; Webcams; Alarm bells, electric; Alarm monitoring systems; DC/AC power converters; Electric door bells; Electric door chimes; Electric locks; Electric wires and cables; Monitor signal amplifiers; Power adapters; Power controllers; Power switches; Telecommunications equipment, namely, fiber-optic transceivers, fiber optic repeaters, converters and optimizers, wave division multiplexers, free-space optics transmission systems, switches including Ethernet switches and rout...