A CocoMat measuring 23" x 20" x 1.2" made from coco fibres. CocoMat holds all the moisture required. Fill your tray just once and CocoMat will water the plants for up to ten days. The CocoMat controls watering by holding and gradually wicking the water to the plants via capillary action. Simply place your CocoMat into a tray, place Root Control Sheet on top if required (Root Control Sheet not included), fill the tray with water, place your seed tray on top and grow!