I have an unconventional setup that houses my chickens in a mobile coop which is outfitted with your egg cartn system.  When the weather turns cool in the Fall I “dock” the mobile coop with a stationary structure so it  effectively doubles the size for the colder weather. Your product enables me to secure a “tight fit” between the two structures. It looks kind of goofy but keeps the birds safe and secure. I’ll send a photo if I can find one. I’m really thrilled with the quality and utility of the egg cartn system. Great design and nice heavy construction!