4 Line Ring Shaper - Booster. The RG-204 ring generator is designed to reshape and increase the ringing power of up to 4 analog PABX extensions, FXS ports, IP phone system analog ports, or any other telecom devices which provides ringing. The RG-204 duplicates the incoming ring cadence allowing it to be compatible with custom ringing features. Each line is capable of ringing four 1 REN or eight 0.5 REN telephones and does not affect normal operation of the telephone line or features, such as caller ID, call waiting, hookswitch flash features, CPC signaling, etc. For larger multi-line applications, use Viking models RG-212 (12 line) or RG-224 (24 line). For single line applications, use the Viking model RG-4. The Viking model RG-10A may be used for single line higher drive output applications up to 12 REN. Applications Boost ringing on FXS ports or IP phone system analog ports that are weak or fail Boost ring power on analog PABX/KSU stations that are weak or fail Reshapes troublesome distorted ringing signals Features True Sine wave ring signal output Boosts ring to 4 REN Caller ID compatible Easy RJ-21X installation Compatible with distinctive ringing services Will not affect normal line operation Reshapes troublesome square wave ringing Fax and modem compatible Not compatible with pulse dialing.