This is a supplementary sign that was affixed to the windows of the Kamikochi Line 20100 series train when it was modified at Keio Heavy Industries and transported by land to the Shinmura depot. It's a simple, laminated sign, but the design is elaborate, resembling the side destination indicator of Tobu Railway trains. I don't think these are often available, so please consider purchasing one. Please note that this item is also for sale elsewhere, so be sure to comment before purchasing. I will not be held responsible if the item is sold out if you purchase without commenting.