I recently installed one. 79.5 cm goes without a problem. The adjustment range is between approx. 75cm and a little over 85cm (you could always clamp a piece of wood or similar in between for more width). It also comes with 4 "plates" that can be clamped in between and fixed with double-sided adhesive tape. I screwed these plates on because they protrude about halfway, as the door frame is very narrow. It holds very well. By the way: The grille has to be tightened quite strongly, otherwise the catch of the door will not engage because of the distance. So don't be alarmed if the door doesn't close, or the grille seems too wide if it's less than 80cm wide! The door can be opened from both sides and automatically falls into the lock or catch from both sides. All in all, a good thing. Only the height of the grille is a bit narrow for our needs.

Unfortunately, I can no longer answer this question, as we no longer have the barrier. However, the dimensions should be visible in the product description.