Review on Aluminum Sash Window Pet Door by IDEAL PET PRODUCTS - Adjustable 33" to 38" Width, Chubby Kat Size (7.5" x 10.5" Flap), White - Model: 33SWDCK, Since 1990 by Mary Cole

I really like this door. A pet door has never been easier. I have 2 Shih Tzu dogs that this works great on. My windows are very low on the inside but taller on the outside due to the height of the foundation. I have steps outside and a protective rubber mat on the inside windowsill that I recommend for dogs. I set up in minutes. It just pops out after you loosen the locks, then lower the window and you're done. The easiest setup I've ever experienced! Worth every penny! This solved my problem with a glass window door that didn't fit in a regular pet door. The window was the best solution. Your window is undamaged, so this is the perfect solution if you're looking to sell or rent it out for the day. It took my dogs half a day to get used to the door. Prop or tape the door and offer treats on each side until they can easily pass either way. Then hold the door open while you offer him a treat and let him touch his head to get him used to the flap. If that works well, put them outside and go in alone. It may take a while, but turning your back on them while you're in sight and holding a bag of goodies will eventually motivate them to use them. I have never recommended a product more than this one. There is an optional window lock that I recommend purchasing to protect the window from intruders as you cannot lock the window once the door is installed. Inside the box is a note with instructions on how to order a window lock if you can't order one with the door. The purchase costs only 8 dollars.