The clamp is made from a special hardened steel and has a rubber sleeve to protect the piano's finish. Clamp has a maximum opening of 6-1/8" wide, which should fit most any type of piano fallboard. A wooded shim is provided for use when installing on pianos with smaller fallboard widths. This device consists of a lock and two keys, which are keyed alike. Screws are provided to attach the clamp underneath the keybed.