The Master Lock Portable Key Safe is a handy addition to an over-the-door-handle security that allows you to store keys for the door you mount this lock to. Featuring a 4-digit combination lock for added convenience, set this lock up over a standard door knob to securely store a number of keys. This lock has a protective weather cover to allow for external application, and moulded body with vinyl coated shackle for protection against scratching.