The Barksbar Large Dog Door with Aluminum Lining gives your dog the freedom to go take a break in the yard and come back to the comfort of your home as they please. The door is easy to install and easy to use， even for dogs that have never used a dog door before. The magnetic strip at the bottom keeps the weather out and the AC in， and the locking panel gives you the ability to protect your home when the door is not in use. To train， simply hold the door flap open and coax your dog through with a treat. Try again with the flap closed， just holding it open long enough for your dog to see you have a treat on the other side. This may take several tries with some dogs， but once they get the hang of it， it'll be a breeze.

• Frame Size: 9.75"-14.75" ; Flap Size: 7"-by-11.25"; Recommended Door Thickness: 1 1/4" to 2"; White Plastic & Aluminum Lining: Keep Your Restless Pet Healthy And Active Without Ever Having To Open A Door Again
  
  
• For Dogs & Pets Up To 40 LBS: Durable Enough To Handle Day-To-Day Use; Bite and Chew Proof Tested; Easily Prevent Any Unwanted Guests From Entering
  

• Soft Flexible Heavy-Duty Vinyl Flap With Magnetic Closure: For Your Pet’s Comfort And Ease Of Use; Will Not Warp Over Time Or Under Extreme Temperatures
  

• Removable Self-Locking Slide Panel - 2-Way Locking: Easily Restrict Access When Door Is Not In Use; Helps Protect Against Extreme Weather， Air Drafts， As Well As Bugs And Insects

• Telescopic Frame: Very Easy To Install With Just 5 Easy Steps; Average Installation Time: 25 Minutes