Custom designed "lid" for American Hydroponics 3' x 3' Econo or Heavy Duty trays. The Net Well holds (24) 5-1/2" Heavy Duty Net Pots (product #724430), lifting them off the bottom of the tray for supreme aeration. This "lid" also creates a cover for the roots of your plants, not allowing any light to penetrate the roots. Achieving the healthiest root zone possible is the key to large, lush plants!