Accessory handset is designed for use with AT&T Dect 6.0 TL86109 Telephone System with Bluetooth capability. Dect 6.0 technology delivers up to 45 percent more range over 2.4 GHz & 5.8 GHz phone systems without needing a boost in power. Handset speakerphone leaves your hands free to do other things & lets more people in on the conversation. Intercom between handsets. Conference between an outside line & up to four cordless handsets. Two-line handset also offers high-contrast backlit LCD & lighted keypad, Caller ID / Call Waiting with a 200-name / number history, any key answer, volume control, last 20-number redial, & ringer volume control. Handset is headset compatible with its 2.5mm jack. Setup menu is in English, Spanish & French. Energy Star qualified.