The VTech DS6151 cordless phone system is expandable up to 12 handsets and features DECT 6.0 technology. With this technology the user can enjoy the best in cordless phone sound quality, security, and range. This system won't interfere with wireless networks and, with the enhanced security features, you no longer have to worry about identity theft . The DS6151 has 50 station caller ID/call waiting that will let you know who is calling even when you are already on the line. Additional features include 50-entry phonebook directory, last number redial, selectable ringtones, page/handset locator, handset volume control, large backlit display and keypad. This energy star qualified phone has a digital answering system with dedicated mailbox for each line. DS6151 Features: DECT 6.0 Technology (1.9GHz) Interference-Free & Wide Range 30% more Battery life 2-Line Operation Caller ID / Call Waiting Expandable Up To 12 Handsets 13 Minute Digital Answering System Microchip Answering System Technology Clearer Recordings & Longer Life 2-Digit LED Message Counter - Time and Day Stamp - Call Screening / Intercept Remote Message Check Voice Menu Eco-Friendly Phone Large Backlit LCD Display Dual Speakerphone (Base & Handset) Backlit Keypad 50 Station Name / Number Caller ID Memory 50 Station Phone Directory / Dialer Selectable Ringtones Adjustable Handset Volume Control Handset Locator / Paging Redial