Convex and ribbed design for strength and drainage. Easily fits inside the reservoir top. Makes sure that water falls back into the reservoirs. Multi drill access points to install meters/pump cords. Convenient access port hole. Overall dimensions: 50L x 50W x 2H in.. About Hydrofarm Inc.Celebrated as the nation's oldest and largest manufacturer of hydroponic equipment and grow lights Hydrofarm has made professional-grade equipment available to all since 1977. All grow lights and electric components are UL listed unlike many competitor products meaning you get years of reliable and safe use out your high-intensity lights. All products are covered by a one year warranty at the least. In some cases Hydrofarm ensures the performance of their products for five years.