- Viking Electronics long loop adapter- Provides 4 long line and off premise extension (OPX) capabilities for PABX and KSU analog stations ISDN terminal adapters channel banks etc.- Converts any four low talk battery boltage or weak ringing analog line into a standard 48V line with powerful 20Hz sine wave ring signal- Compatible with pulse dialing touch tone dialing hook switch flash features CPC signaling and Caller ID features- Ground screw terminal allows for improved surge protection and as an ear