The hinges are for mounting under the surface of a table with leaves that drop down. They are most commonly used with rule joints. If you would like some instructions on how to install rule joint hinges, let us know in the "comments" section during checkout and we will include them.
One of our strengths is our ability to deliver hardware quickly. We maintain substantial stock and we take pride in the fact that if you order 50, 100, 200, or even 1000 items, we will be able to ship your hardware promptly.