AC adapter with a round connector. Cigarette lighter socket part / Diameter: approx. 2 cm, Length: approx. 7 cm This item has arrived at my home in the last few years, but I have no idea what it was for. I think it's something you use by plugging it into a car's cigarette lighter socket. I'm sorry, I'm not very knowledgeable. I haven't opened the bag, and I haven't checked if it works, but I thought I'd list it in case someone needs it. (I opened it once for the photos.) - Type: AC adapter - Connector shape: Round - Cable length: Standard length Thank you for looking.