Window kit panels are designed to fit the standard sliding window. However, if your window's opening is smaller, you can trim the boards to make them work.
Remove all of the panels from the packaging. Unfasten the straps and uncoil the hose. Remove any excess plastic or packaging material from the sides of your unit.
Slide the panel farthest from your exhaust hose into your sliding window until firmly in place. Then slide the second panel into place next to it. Finally, slide each additional panel until you have one left to fit into place.
Measure the distance between this last remaining panel and the side of your window.
Use a utility knife to trim the remaining panel to match this distance. Do not cut or trim any other panels.