The Clarity D704HS is an expandable cordless handset for the Clarity D704, D714, & D724 Amplified Cordless Telephones. The D704HS Expandable Cordless Handset will ONLY work in conjunction with the D704, D714, & D724 Amplified Cordless Telephones. The D704HS will NOT work alone. Patented Clarity Power technology clearly amplifies incoming sounds up to 40 dB DECT 6.0 interference-free technology Adjustable tone control Loud and clear handset speakerphone Easy-to-read Caller ID display Large backlit keypad is largest of any cordless phone Backlit keypad and CID display act as visual ringers Ten (10) loud-and-clear ringtones with six (6) levels of volume Includes belt clip and 2.5 mm headset jack Hearing aid compatible Expandable up to five (5) handsets One (1) year warranty