Sonic Alert Amplified Telephone Audio & Video Component Amplifier,Grey (AMPLI555) Large 1" back lit easy to see and hear talking keys Extra loud amplification, with True Sound up to 52Decibles of extra clear Sound Answering machine function with easy to understand slow message playback 95Db loud ringer & built-in strobe Ring signaler Calibrated easy to adjust volume and tone control, settings stay in place