Thermo Sash 3e Cat Door for Sash Windows Pet Doors A single flap design gives

A single flap design gives many pets a more natural push through experience than heavier double flap systems

It secures the locking cover in place

Its reinforced shape increases strength

The telescoping aluminum tunnel is a defining part of that experience

Easy for pets to use: The flap is slightly foggy but still see-through

Thermo Sash 3e Cat Door for Sash Windows Pet Doors A single flap design givesThis insert is built specifically for vertical sliding windows, allowing you to add a pet door without cutting into walls or doors. It sits cleanly within the window track, preserving the look and function of your home. Quick Setup No CommitmentThe spring loaded design holds the panel in place using pressure within the track, so installation is fast and removal is just as easy. This makes it especially useful for renters or anyone who wants