Purchased at a Keikyu event in 2019. It says "821-1". After purchase, I only rewound the curtain and removed the fluorescent lights to prevent damage to the curtain, but I haven't done anything else. It doesn't work as is, so I haven't been able to confirm the operation of the drive unit. As you can see in the photos, the curtain is also quite dirty. Please purchase if you are able to handle cleaning, modification, and returning the curtain yourself. Due to the nature of the product, there are some scratches and stains. Please understand the above before purchasing. The earliest shipping date will be October 16th due to collection arrangements.