Wanted to love these but...
I have 2 big cats, one Maine Coon and one Ragdoll.
There simply wasn't enough litter included on top of the liner for them to bury their solid waste, so it sat on the surface and the odour of fresh cat poo circulated freely until it was removed.
i found myself having to add top up litter, but that added to the depth of the liner meant the tray was overfull and litter ended up everywhere!!
+1 of my cats hated the liner itself and savaged it at every use!! Oh dear!!