The EH4104R single zone fire RF receiver with relays is designed for use with the Inovonics EH1115EOL EchoStream single input fire RF transmitter to monitor water flow and pressure in piping and post indicator valves to send an alert when a fire protection system has been activated. The EH4104R single zone fire RF receiver with relays allows you to add a transmitter to any application. With diversity re- ception and advanced signal processing, Inovonics EchoStream technology is designed to minimize dead spots in transmission areas.