42" Charleston Wall Trough with Coconut Liner, Set of 2 These Charleston models are deeper and larger than standard window boxes in order to retain moisture longer. The Charleston Wall Troughs are 9.5" wide and 10" deep and come complete with a natural preformed coconut liner. Dimensions: Approximately 42" L x 9.5" W x 10" D These Coco Liners are sold only as a set of 2.