System Sensor M501M Intelligent Addressable Mini Monitor ModuleThe System Sensor M501M Intelligent Addressable Mini Monitor Module is intended for use in intelligent, two wire systems where the individual address of each module is selected using rotary decade switches. It provides a two wire initiating circuit for normally open contact fire alarm and security devices. The M501M monitor module can be installed in a single gang junction box directly behind the monitored unit. Its small size and light weight allow