Outer Dimensions Are 17.5" Wide x 12" Tall x 2.75" Deep - Will Fit All Garage Doors - Insulated And Non Insulated Garage Doors [The Hole In The Door Should Be: 15 ¼ x 9 ¾] Made of High Quality Aluminum That Will Never Rust Control Lever To Adjust Louvers According To Season - Completely Open For Summer To Release The Heat, Closed For Winter With Mesh Guard To Maximize Ventilation Results, Install 2 Vents. One Towards The Top Of The Door, And One Towards The Bottom Of The Door. This Will Create A Cycle Of In And Out Air Flow. As The Hot Air Will Flow Up & Out, And The Cooler Air From Outside WIll Flow In From The Bottom