Heavy Duty Dog Door® Weather Tight Chew Proof Indestructable Energy Efficient Easy To Install Fits Dogs Up To 120 lbs. Includes: heavy duty spring hinges, 1/4" clear plexiglass and die cast aluminum frame. 12 1/2" X 17 1/2" cut opening. 14" x 20" frame. Manufacturers lifetime warranty, includes chewing. Heavy Duty Dog Door® G-HEAVY$89.99 Optional Drop-in Closing Panel For The Heavy Duty Dog Door ®...Prevents Entry And Exit.Optional Drop-in Closing Panel For The Heavy Duty Dog Door® ...Prevents Entry And Exit. To keep a pet from entering or leaving. The 1/4" polypropylene slides inside a double track aluminum channel. You can use the Drop-In Closing Panel on a door, shed, garage wall, etc. The Heavy Duty Dog Door mounts on the outside and the Closing Panel mounts on the inside Optional Drop-in Closing Panel For The Heavy Duty Dog Door ®...Prevents Entry And Exit. G-HDCLOSE$29.99