High-Efficiency, Grey, Talkback Horn is weather-resistant for indoor/outdoor applications. Works will all Valcom talkback page controls. – Weather Resistant Enclosure. – Omni-Lock Mounting System. – Utilizes Standard Telcom/Datacom Wiring CAT 3/5/6. – For Paging And Handsfree Talkback. – Includes I-Beam Clamp.