This device is is necessary if you have an Old Rotary telephone which you still want to
use with digital telephone service. This will convert Pulse dialing to DTMF tones which are compatible with the modern VOIP (Digital) service and work on low voltage VOIP Digital service like Magic Jack, AT&T U-verse, Comcast and many others. Asterisk (*) and Pound
(#) keys also work as well as six (6) speed dial #'s and last number redial. Plugs in-line
with your line cord, NO batteries required and has a user guide.