public address (pa) systems, beacons, charged coupled device (ccd) cameras, communication systems, communications engineering, intercommunication equipment or systems, loudspeakers, signaling systems, security system design, talkback amplifiers, monitoring system technical services, audio evacuation systems, paging amplifiers, security system technical services, emergency audio communication systems, emergency telephone systems, industrial paging systems available from gai-tronics corp based in reading, pa. click the links below to visit our website or contact us via our profile page.