8 Port Telephone Expansion ModuleDesigned to support up to 4 incoming telephone lines with 8 outputs/extensions per lineModule is bridged as using only 2 incoming lines can get 16 outputs/extensions per line and using only 1 incoming line can get 32 outputs/extensionsIncludes an RJ31X jack connected to line 1 for a security systemIncludes an expansion jack for more outputs/extensions by connecting to ICRESVPB10 8-port telephone resi module with expansion jacksFits all ICRESDC 14 21 26 AND 42 residenti