I installed this on a horizantaly sliding window.  It probably took about 10 to 20 minutes to install.  Its just 4 screws. It comes with a guide for the position of the screws which helped. It works awesome. You even have to put a door stop infront of a door in a beadroom if you have the fan in the room blowing the air in, otherwise its strong enough to slam your door shut. We liked it so much so that we bought a second one and installed it in the kitchen to clear the air when we are cooking.  we will usually put the fans on exaust and open up the living room window and it pulls in a strong breese with them both sucking the air thru the house.