These black Seedling Germination Trays are used by professional nurseries. Also called No Hole Flats and Leak-Proof Seedling Trays. Use with 12-cell, 24-cell, 72-cell, or 128-cell planting inserts. Protect your house from spills.These flats are also sized to work with the clear domes, lighting systems, and seedling heating mats. Seedling Germination Trays add stability to the cell inserts, which allows you to move them as needed. These trays do not have drainage holes, so they catch any water that leaks through your cell inserts. They can also be used to manage Peat Pots, Cow Pots, and Coir Pellets more easily. Each tray measures 28 x 56 cm (11″ x 22″).