For details, please refer to the homepage related to this product, antique experts, or information from other sellers, hosted by specialists. I cannot explain it, so I don't know its purpose. It might be a key cover to hide the number part of the key. I don't know the details. I apologize, but I cannot answer any questions. We do not accept discounts or price reductions for this product. We will refrain from replying to comments requesting discounts or price reductions. Please understand. I have many images remaining, so please be sure to check them. To prevent trouble, please examine the images carefully. Please refrain from purchasing if you are sensitive. Please be sure to read your profile before purchasing. We cannot provide any guarantees or compensation for not reading it. This is for those who are okay with the above. #keycover ?