Someone else wrote "doesn't come with a power adapter"... well, it's not supposed to, so the fact you left a 1 start review because you don't understand the product is a horrible thing to do to a company. You unplug your home-base, and then plug the plug you just unplugged into the battery backup power hole. The take the little plug on the battery backup and plug that into the homebase. Not rocket science. Works good. I use it with my home-base3. It doesn't fit under our, so I plug it in, and leave it sit next to it, works good just doesn't look the best, but still works!!!