When I seen this bell I knew I needed to have one, so I also got one for my store. If you love bells, you need to add this to your collection. They are made to be mounted on your door so when it opens, the bell rings to let you know someone is there. It measures approximately 10 inches and it comes with mounting hardware. Just a slight clue.. the top screw hole is behind the bell.. I screwed the screw in at an angle and it worked great.