Litter box liners are for cat litter boxes, and ferret litter boxes. They make the job of changing litter a bit more simple, in that you don’t have to pour the old litter in a garbage bag. You just take the liner, tie it up and throw it out.
Litter Box Liner:
Litter Box Liners pictured:
Van Ness DL715 PureNess Extra Giant Drawstring Cat Pan Liner, 15-Count