electronic telephone line branching switches for voice/data devices, namely, telephones, telephone headsets, telephone answering machines, facsimile machines, modems and point-of-sale machines, computer modems; electronic and/or computerized security systems, namely, control units, base and remote sensors, namely, temperature, motion, sound and light sensors, electrical switches, signaling devices and telephone dialing units for use in residential and commercial property; local area paging systems, namely, a transmitter base station and paging receiver; computer facsimile interfaces; telephone toll restriction circuits; telephone selective ringing and routing switches; interface cable assemblies for computers and cellular telephone systems; DC/AC power converter units; telephone line exclusively switches; miniature digital calculators; computer facsimile receivers and interfaces; adaptors for remotely changing telephone call forwarding services; and telephone line monitoring and emergency alarm circuits