This is a "cat-foot tabi" (socks) for the 13-string koto. I made these after a previous customer requested a "bag" to hold "cat feet." I made more for others who might need them. They are made from repurposed, unused fabric, double-layered for durability. ★Size: Approximately 20cm (height) x 17cm (width). Please note that there may be slight variations in size. I made them as "cat-foot tabi," but you can also use them to hold other practice tools (such as a tuning whistle or tuner). Please use them to store various items for your practice.