Talk Battery Booster, screw terminal connections for easy installation, boost talk battery to 48V, boost loop current to 26mA, alarm panel compatible, power supply included. The TBB-1B will boost talk battery voltage up to 48VDC, and current up to 26mA on single analog line extensions behind PABX s and electronic key systems. This is helpful for powering line powered devices such as touch tone dialers and emergency phones on low voltage and/or low loop current extensions. When the TBB-1B is being used, the power LED lights extra bright to show activity. The TBB-1B is not compatible with Pulse/Rotary dialing. Applications Run line powered devices such as handsfree phones, touch tone hot-line dialers, digital announcers, etc. Increase maximum loop length on analog PABX/KSU stations Use with wireless doorbox devices Features Boost talk battery voltage up to 40VDC Boost talk battery loop current up to 26mA Power LED also displays activity Passes original ringing through to the device Passes caller ID data Passes hook switch flash Passes CPC signals Power adapter included Compatible with touch tone dialing Note: Not compatible with pulse/rotary dialing.