There are 12 programmable buttons with LEDs that can be set for line selection, intercom calls, speed dialing and features, plus 12 programmable buttons without LEDs. Redial of busy number. Conferencing. Bright LED in top right corner indicates ringing or message waiting. For desk or wall. Second & third lines on display work only with with KX-TA624 "DASH FOUR" and later. 3-line backlit LCD Speakerphone.