A few nice Phones images I found:
Image by @Doug88888
Image by sheldonschwartz
Image by zackaholic
It’s a speaker… in a phone! The kind of cool thing is that the power switch is wired to the phone cradle switch so to turn it on you just take the phone off the hook. It doesn’t run off power from the phone jack, but it could will a little extra effort. The jack in my room is dead, so this one’s wired to a wall wort.