Review on MAVRICFLEX Weatherproof Dog Door with Sliding Lock Panel | Energy Efficient Large Aluminum Dog Door | Easy Installation | Magnetic Flap Heavy Duty Dog Door for Dogs Up to 200lbs by Ruth Haiar

First of all. 1. No real tracking pattern. 2. You use the opening provided. The problem is that it's not big enough to add the included plastic pieces to fully close the door once it's cut and installed. The rivets that hold the screws on the back of the door are installed poorly and when you try to put the screws in they start turning with the bolts and now you can't tighten or loosen the bolts. You are useless. I would have to cut them in half and cut them out of the door. It's a shame that I really wanted to return this thing. I cut off the ends that came through a bit and used a grinder to cut off the rest and used drywall screws to get this thing working. like I said, it wasn't worth ripping it all apart after this thing hit my door. Oh, and I have a metal door, mind you. I had a meat grinder, so I could negotiate on this subject. Again, there is no exact pattern. Garbage rivets... do yourself a favor, buy one of these with an excellent rating... I don't usually write minor things, it's very bad or very good, and this product is awful.