Portable Push Button Lock Box, 3-1/8" (79 mm) Wide Metal Body For Durability, Shackle Design Offers Over The Door Mounting For Convenience, Set Your Own 4 Character Combination For Keyless Convenience & Increased Security, Protective Weather Cover Prevents Freezing & Jamming, Molded Bumper & Vinyl Coated Shackle Prevent Scratching.