This is a simple server that attaches to canned beer. The following is a quote: This easy-to-use beer server creates creamy foam just by attaching it to a can. It uses ultrasonic waves to create fine-grained foam. The creamy foam prevents the flavor from escaping. It's cordless, so you can place it anywhere, and its compact size makes it convenient to carry! You can use it for leisure activities and outdoor adventures. Compatible with 250ml, 350ml, and 500ml cans from Kirin, Asahi, Sapporo, and Suntory. *Not compatible with imported beers. There are no instructions or box, so it will be shipped in a Yu-Packet Plus box. Please note that the packaging will be minimal as it will be packed tightly in the box. Used only once or twice and then stored. Instant purchase is welcome if you have no concerns◎