Post Alarm Systems 47 E Saint Joseph St, Arcadia, CA91006 Post Alarm Systems is one of the largest alarm companies in the country. Founded in 1956 by former police chief Rob…More Post, it has been owned and operated by the Post Family for more than 50 years. Post specializes in state-of-the art alarm systems, 24-hour monitoring with emergency response, and armed security patrol services. It also offers residential and commercial alarm installations, consultations and all related services. Other systems include fire and burglar alarms, video surveillance, commercial monitoring and alarm response and patrol. This Arcadia location is the flagship office. The reception area is comfortable and modern, with an electronic code entry system. Back-up systems continue to operate even in a power outage or interrupted phone service. For more information, call toll free at 800-654-7678 or visit the website.