I have the cat litter box in my cat hotel with several copies in continuous use, and it is well accepted by all cats. Time with hood and sometimes without. And even without a hood is super because of the high margins because no cat litter flies out. And in Cats Hotel I have to yes to all possible litter users adjust :-) However, I have taken the same door and filter out at the hood. The flap does not really (although it is good and smooth), and the filter is in my opinion, nonsense, because if you keep the litter box clean beautiful, then only produced no noticeable odor, or :-)