We developed our DFT hydroponics rack trays with professional growers in mind.The key is that a set of DFT hydroponic tray has four growing functions.The first feature is the nursery grow trayThe second function is the microgreen growing trayThe third function is the micro vegetable grow Plastic to Go BoxesThe fourth function is a salad vegetable planting trayThe most amazing thing is that the bottom DFT hydroponic Plant Tray is universal, you only need to replace the growing function tray.