This Portable Waterproof Key Lock Box is durable as it is made of the best quality of heavy-duty metal and will deter thefts in public and private settings. Our lock is made of a zinc alloy which makes it resistant to water, sand and salt erosion. ThePortable Key Lock Box is easy to operate, yet the hardest to break into. Portable Key Lock Combination Box can be used for Home, Vacation Rentals, Businesses, Real Estate, Office, Gym, Hospitals, Schools and Warehouse. Removable Shackle is easy to install over a doorknob, fence, locker, gate, garage or anywhere you need to install a lock box, and it can be placed anywhere. Easily transportable from one location to another. A Removable Shackle makes it easy to placeon doorknobs, a wide fence or anything that is oversized. Cover should be up to keep it the combination from getting jammed or stuck. Protective Outside Layer is made from a unique and hard plastic which is one of the strongest plastics in the World that is unbreakable. This makes it the perfect material to deter thefts in public and private settings and to protect your keys and cardsfrom being damaged by drill, hammer, saw and flame retardant. Also, the outside layer is scratch resistant, so it wont scratch your door or anything you hang it on.