The Endura Flap Custom Cat Door for Horizontal Sliding Windows offers an energy-efficient, custom-fit pet opening designed specifically for horizontal sliding window tracks. Engineered with heavy-duty frame construction and high-performance flap technology, it provides your cat independent freedom without requiring permanent window modifications.

Custom Fit for Sliding Windows
Custom built to your exact window dimensions, this insert slides directly into your existing window track for a secure, draft-free seal. The spring-loaded design allows up to 3-1/2" of built-in height adjustment, making installation and seasonal removal quick and tool-free.

Heavy-Duty Frame & Safety Glass
Available in durable aluminum or vinyl frames to match your home's aesthetic. Aluminum models fit tracks at least 1" wide, while vinyl models require tracks at least 1-1/2" wide. The insert features single-pane safety glass for maximum natural light and energy insulation.

Award-Winning Weather Protection
The patented Endura Flap utilizes magnetic seals and dual-pane construction to stay sealed in wind gusts up to 50 mph and remain flexible in temperatures down to -40°F, ensuring optimal year-round thermal protection.

Enhanced Security & Locking
Every panel includes an Endura Flap Slide Lock to secure your sliding window track, alongside a sturdy top-loading Endura Flap Locking Cover to control pet access when needed.