Works fine. About 3 years old. Has power supply. 2.4 GHz spread spectrum.  Never had any interference from other devices.  Voice quality great.  

Features: Has speaker phone mode for while doing dishes, and a headphone jack for healings. Hold button, flash, redial, volume adjustment, mute (so you can talk to your child while the other person goes on and on), handset locator (for when your child took it and you don't know where the handset is), voice mail indicator light (for when you pay the phone company for voice mail), call waiting (for when the other line is ringing while you're talking).  I believe it does conference calls between the 2 lines but I'm not sure.

In other words -- it is full featured.  I think the original price was about $ 89.