The addition of a Window/Maxx to your RV's sliding windows, provides refreshing cross ventilation even in the rain. Ideal for pets. Helps eliminate heat build-up, smoke and cooking odors. Works great with fan-powered roof vents. Easily trims to fit virtually all RV sliding windows up to 33" tall. Mounts to the exterior frame of either right or left hand sliding windows and will allow them to fully open and close as before. Stainless steel mounting hardware and adjustable window stop help to maintain vehicle security even with the window partially open. Tough, high impact polymer with UV inhibitors.