The Patio Pacfic Thermo-Sash 3e Sash Window Pet Door includes dual-pane, insulated, low inchesE inches glass plus the award-winning Endura Flap, Exclusive - Every Thermo-Sash 3e includes the award-winning Endura Flap pet door -- the best engineered high performance pet door flap ever made, Exclusive -The Endura Flap is guaranteed for 15 years!, Exclusive -The Endura Flap won the coveted Fancy Publications Editors Choice for 2007!, Dual Pane, Insulated Low inchesE inches Glass is the highest performing glass available, It is standard on the Thermo-Sash 3e, This glass unit is guaranteed for 10 years!, Spring Load design can be installed and removed in seconds, No Tools installation, Exclusive -Built-In anti-whoops allows for, 75 inches change in adjustment range to allow for small measuring errors, Draft Stopper - Keeps air from coming in between the two windows, Adjustment Ranges accommodate windows 22 inches - 43 inches wide in 3 inches increments, Be sure your track width is at least 1 inches, 100% Designed, engineered and manufactured in the U, S, A, Dimensions: 27 inches L x 3 inches H x 38 inches W SKU: PTPC137