More efficiently manage phone traffic with this accessory handset for the CM18445 Four-Line Business System. Dial & receive calls on up to four different phone lines. DECT 6.0 digital technology delivers superior-quality technology, which provides strong protection against wiretapping & the best, interference-free call range. To install, simply connect the power cord & push the registration button. Lines: 4; Telephone Type: Cordless; Caller ID / Type: Handset; Volume Control: Handset.