(1) The cat door is specially designed to fit all sliding glass doors and glass windows. It fits 99% of sliding glass doors for cat door installation. This will be the only sliding glass pet door on the market.(2) The Cat door will blend seamlessly into your existing sliding glass door or window as it is a circular shaped translucent door made from one of the most resistant materials: polycarbonate. It is UV stabilized so it will not fade in the sun of Europe and the United States.(3) The is suitable for glass installations, including sliding glass doors. The is suitable for most dogs and cats up to 8 kg.(4) Hole size: 267 mm in diameter for the glass. Glass doors are designed for 3mm to 25mm glass panes and most ranch slides with over 21mm clearance.