This is a very popular Hehr window operator which is no longer available. We came up with this kit for a trailer that we were restoring and it worked great so we decided to offer it to our customers. It uses the existing mounting holes which are approximately 5-1/8 inch apart (center to center). Kit comes with operator, mounting bracket, mounting screws, and nylon friction pad. If you are missing the original back frame grommet you will need to use over-sized screws.