Thank you very much for your interest in my products among the many Mercari listings. This is a USB LED light, blue. I bought a bunch of these a few months ago, but I no longer need them, so I'm selling them. First, regarding how to use it: plug it into a USB port, turn the key cylinder ON, and touch the top of the glass tube with your finger to turn it on. You can also adjust the brightness by long-pressing. * When you turn the key cylinder ON, it will flash briefly, but this is not a malfunction. This is a retro-style USB light. It's surprisingly bright, so you should be careful when using it while driving. This is new and unused, but I turned it on once for the photos. Finally, as this is a delicate electronic component, I will take care to prevent damage during shipping, but if it doesn't light up, please feel free to comment in the message section. Thank you very much.