"I don't know about everyone else and their "10-20 minute installation" but there were a few flaws. I have to admit that if you were just to throw it up, and leave it without any type of security then it takes second. But, even if you take the time to install the lock, there is nothing stopping you from just pulling the whole thing with the pet door locked onto your sliding glass door to open it. Basically, you have to drill and screw the pet door (which they don't provide) into your house frame to secure it. Also, the lock they provide doesn't line up correctly if you have double paned doors. We ended up using one of the patio door locks on the bottom rail (like the ones from the 70's) from Home Depot. We made a lot of trips to Home Depot to complete this installation (approx. $8 more). After everything, it was worth it because if we were to ever sell our home, we could take it with us with minimal damage."