Freedom Pet Pass Door-Mounted Energy-Efficient, Extreme Weather Dog Door with Insulated Flap DoubleMag technology gives an airtight and weatherproof seal for the only truly draft-free dog door; lab-certified to seal 15X better than the requirements for Energy Star human doors Insulated flap system keeps your house comfortable even in extreme conditions; proven to work from temperatures as low as -40 F to as high as 160 F Comes with easy-to-use locking clear acrylic security panel Pet opening: 11'' x 17'' | Rough opening: 15'' x 21.5'' For installation in an exterior door