The liner is small for the box
Hi Denise, it looks as though the incorrect liner type may have been ordered for your Modkat XL. We're emailing you directly now to help!
Flip Liners - Type F (3-Pack)
I have three ModKat litter boxes for my two furpeople; the liners are wonderful, very tough. You really can't rip these things and neither can kitty. I'll never buy any other litter pans/liners than from ModKat.
Best litter box ever hands down
I have 3 ModKat Flip Top boxes and I replace the liners in each about 1x-2x a year. They hold up well for long periods. If the litter liners are really soiled (I notice some litters work better in them than others) I will wash them, hang to dry and re-use. Really the only time I have to change them out is when they have been clawed up a good bit by the cats. The fit the boxes quite well, although if it was me, I would have added 2 more hooks in the middle to keep them in place. I do notice sometimes they sag a wee bit in the middle where they are not hooked to anything. Overall very pleased with them, they keep the boxes in pristine shape and from being scratched up.