This is a diving computer, the Calm. I purchased it in September 2019. It's solar-powered, so you don't need to replace the battery. There's a protective sheet on the LCD screen, so there are no scratches on the screen. It also has a light. I've done 245 dives with this dive computer. I had another one before this and logged about 750 dives, so this one still works perfectly fine. However, it was stolen on a boat. I was finally able to find it, and since then, I've been writing my name on it out of frustration. I wrote my name on the front and also on the back. I've erased most of the name on the front, but it remains on the back. You can't see it when it's on your wrist. Sorry about that. It comes with the instruction manual and the box. I have the serial number of the dive computer recorded in the manual from when I bought it. My name is written on the black part in the fifth photo. Please refrain from purchasing if you are concerned about any of these aspects.