These are the rubber bands for the dougake (chest protector). A set of 3: 2 purple and 1 crimson. They are thin, so they don't lift up and fit comfortably on the chest, making them easy to use. I purchased these new as spares at a traditional Japanese musical instrument store, but I'm selling them to someone who can use them, as I'm organizing my storage. Please check my profile for more information. Thank you very much.