We designed this system for many seasons of successful seed starting. The leakproof tray holds 24 individual cells, so you can bring the ready-to-transplant seedlings to the garden without disturbing the other plants. That way they can continue to grow until they, too, are ready for the garden. We even tapered the cells so seedlings are easy to remove. Galvanized steel 12-5/8" L x 8-1/2" W x 2-5/8" H overall Each cell is 2" sq. at top, 1-5/8" sq. at bottom x 2-1/4" H Holds approx. 19 cups of soil Gardener's Supply Exclusive