This is a convenient anti-crime buzzer/key case with a reel, allowing you to retrieve your keys while it's attached to your school bag (randoseru). The reel extends up to approximately 45cm. The back can be attached to the shoulder strap of a school bag using Velcro. It prevents crime by keeping keys out of sight, and also prevents loss. It has a convenient ring for attaching an anti-crime buzzer. I bought this for my child and cut off the tags, but I haven't used it. I bought it thinking it would be easy to take the house key in and out, but it seems I don't need it...