Note: Please have a look at specs image to verify the door you order is the right kind size in your needs. This PX-1 (Medium) door is appropriate for most dogs as much as 30 lbs. If your dog is 30 pounds or overweight, please measure to verify the dog panel will likely be large enough. In the event you don’t seem to be sure, it’s best to reserve the large size door (PX-2).