Review on No Busy Phone Line Adapter by Betty Tucker

I didn't buy this for the loud ringer if you're interested, there are a few rings and a volume control to choose from and it will likely suit your purposes. Bought for my father who often forgets to hang up. If you don't hang up and get an incoming call in the box, it rings, the phones don't ring and you can only answer on the phone that didn't hang up. If you try to answer another extension, you cannot connect. I hope one day I can teach my dad to press the hang up button on all phones when he hears a tone. No luck so far, I have to drive up and hang up.