I bought the largest size and it works great. Very easy to get litter out of and does not bother the cats at all. I like it so much I have bought 5 in total, some Grey, some black because i forgot what color i had lol. I keep 2 next to each other for 2 litter boxes because of how I have them but I just vacuum under them, where the seam is as the pad doesn’t leak, when I feel it needs it or am cleaning anyway. Will buy more if I put more litter boxes down.