This is the telephone with a built-in answering machine that plays back messages slowly for easier comprehension. Calls and messages are loud and clear thanks to the telephone's powerful amplifier which increases the call and message volume up to 50 dB and adjusts the tone for optimal clarity. Pressing the Slow button decreases the speed of messages by 50% for unmistakable understanding during playback. Bright visual ring lights on the base and handset indicate incoming calls, talking caller ID and call-waiting functions (services required) announce callers, and LED-backlit 1" x 3/4" oversized number keys "speak" to affirm a key was pressed. Its built-in phonebook keeps a log of dialed and received calls; includes three one-touch speed-dial buttons. Operates on the DECT 6.0 frequency. Supports up to five handsets. Compatible with hearing aids equipped with T-coil (telecoil). Base plugs into AC with included adapter. Base 3" H x 6 3/4" W x 5" D; handset 7" H x 2" W x 1 3/4" D. (2 lbs.)