Hydrofarm CK64002 Heavy Duty Flat Cell Insert for Plants, 72 Cells Heavy duty cell pack insert Use this cell pack insert with coco plugs, or regular soil or soilless mixes to plant seeds or cuttings Fits into heavy duty cut kit tray and all standard seed flats Start up to 72 seedlings, 72 cells Measures 21-1/2-inch length by 10-1/3-inch width by 2-2/5-inch height