This is a new, unused spacer for a bicycle wheel with hydraulic disc brakes, to be installed when the wheel is removed. I'm not sure of the exact details, but it's approximately 2mm thick. It will be shipped free of charge from Kumamoto via "Yu-Packet Post Mini." It seems it will take some time to arrive; for the Kanto region, it's expected to take about 5 days from shipping. Please note that the tracking status on the web will show as "accepted," and tracking will only become available the day after it's dropped off at the post. Feel free to ask any questions you may have!