1. You will need to select the correct spacer for your glass thickness
2. We include Filler Blocks that help locate the pet door in the glass notch.
(Providing us with the glass thickness ensures you recieve the correct filler blocks)
If you are unsure how to order the correct IN-Glass pet door we highly recommend calling a glass professional in your area,. They typically will come out to your house to take needed measurements so that you can place your order or if you prefer simply contact on of our listed IN-Glass installers and they can handle the entire process for you.