This Ditek® DIALER SURGE PROTECTOR is a modular “plug and play” device, designed to protect fire and security system dialer circuits. A point-of-use surge protector, it can be easily installed in series with the circuit. It comes standard with a single pair of RJ31X dialer circuit protectors and patch cord, an RJ45 modular jack with external grounding screw, and Sneak Current Protection – SCP (150 mA self-resetting fuse protects against repeated surges). RoHS and UL497A compliant.