You need to measure your sliding door height from inside bottom channel/track of your glass sliding door all the way to the top inside channel.
Our Standard Pet Door Inserts fit between 2.0 – 2.1m tall.
If your sliding door is taller than 2.1m, please see our page: custom height pet door inserts.
Please dont forget to measure the door frame width also. Our side channel of pet door insert is 2cm wide, so if your channel is less then 2cm wide, please email us some photos to see if there is a solution for your Sliding door.