Now you can leave your sliding windows open rain or shine! Lets in fresh air, but not rain. Ideal for pets. Provides great cross ventilation with roof vents and fan powered vents. Mounts to the exterior frame of the window allowing it to open and close as before. Stainless steel hardware and window stop pin help to maintain vehicle security even when the window is partially open. Fits right hand or left hand sliding windows up to 33" tall.