Ideal Pet Products Aluminum Sash Window Pet Door, Adjustable to Fit Window Widths from 27" to 32", Cat Flap 6-1/4” x 6-1/4” Flap Size
Specially designed for sash windows and comes with a spring loaded locking slide and clear vinyl flap on standard plastic pet door models or a 4-way lock and unbreakable lexan flap on cat flap and chubbykat door models