I absolutely cannot say enough good things about this. My son LOVE it. We use it as a timer at night--he gets 15 minutes to read on his tablet after lights out, so we turn on the moon and when it goes off, he knows it's time to put the tablet up. He then switches it to eclipse mode which emits a red glow that he finds soothing and puts him right to sleep. In the middle of the night, he turns the moon on full moon so he has light to get in and out of his room by. It also sets itself to match the phases of the actual moon outside--a neverending sense of amusement to see if it's right or not. To hang it, it actually has markings on the back so you know how to orient it. The biggest problem we have is losing that itty-bitty remote. I finally velcroed it, so it attaches to his bed, in easy reach. Now getting g him to USE my add on feature? Totally different story. Now it uses batteries, but I have not changed them in eight months. There is a place you can actually put a cord in and plug it into the wall, but I never used that feature.