Preformed Coconut Liner The preformed coconut liner keeps your window box neat and tidy inside, and connects it to nature outside. These coco liners create a ���down-to-earth" feel and enhance the planters�۪ connection with nature. They keep the aesthetic design of the planters from being spoiled by unsightly roots and dirt, but still produce the effect of a natural growing environment. Perfect Match These preformed Coco-fiber liners are made to drop right into your existing Charleston style 36" window box. Dimensional Considerations This liner will fit the 36" Charleston Wall Trough which measures approximately 36" Long x 9.5" Wide x 10" Deep Important Please measure your existing window box to ensure that these liners will fit.