Equipped with DECT 6.9 digital technology, this accessory handset with charger is designed for use with AT&T answering systems with Caller ID/Call Waiting including CLCL81201, CL82401, CL81301, CL82201, CL82301 and CL82311. High-contrast backlit LCD on the phone shows the name, number, time and date of incoming calls. Handset includes 50-name/number Caller ID history. It doubles as a multiple-handset walkie-talkie to instantly communicate with up to four units in your home. Handset speakerphone allows you to speak and listen without holding the handset. This leaves your hands free to do other things and lets more people in on the conversation. Choose from four preset audio profiles or use the equalizer to personalize bass, treble and natural tones for your individual hearing needs. Handset also includes a nine-number speed dial, last 10-number redial, voice-mail waiting indicator, quick-access key for voicemail box, mute and any key answer. Setup menu is in English, Spanish and French.