I have a three piece plastic louver set that I purchased from JC Whitney years ago. I used them on my 1990 small Nissan hard body pickup truck. These were made for a small pickup truck with a slide open rear window. How these install are the edges tuck under the rubber trim around the window securing them in place. The center piece had 4 pieces of velcro to remove it when the center window was open or you could leave it in place while the window is open.