Benefits Notes Type-G liner refills for the Modkat Tray Constructed of rip-resistant tarpaulin The liner overlaps the base to keep mess inside Easy to empty and clean One liner lasts up to 3 months! 20 x 14 x 9H in. (50.5 x 35.5 x 23H cm) A clean litter box makes for a healthy and happy cat. We recommend replacing Modkat Reusable Liners when there are signs of fraying, or after 3 months time to keep bacteria and odor in check. The integrity of the liners depends on how many cats use the litter box, how much litter is used, and how ferociously they scratch. Daily scooping and sustaining the litter level at 2-3 inches (5-7.5 cm) will maximize their life.