Ring Booster, 15 REN. The RG-10A ring generator is designed to increase ringing power of an existing telephone line, analog PABX extension, analog ISDN Terminal Adapter port, or any other telecom device which provides ringing. The RG-10A duplicates the incoming ring frequency and cadence allowing it to be compatible with custom ringing features. The RG-10A is capable of ringing twelve standard (1 REN) telephone devices and does not affect the normal operation of the telephone line or features provided by the phone company such as Caller ID and Call Waiting. Applications Boost ring power out of ISDN Terminal Adapter Analog Ports. Use with Viking Doorboxes to increase the number of phones to ring. Boost ring power on telephone lines or analog PABX stations that are weak or fail. Correct ring waves from equipment such as automatic fax switches Features Boosts ring to 12 REN Caller ID compatible Easy modular installation Compatible with distinctive ringing services Will not affect normal line operation Reshapes troublesome square wave ringing Capable of boosting talk battery and loop current Made in the USA 1 year warranty.