The CCH2O module lid was designed for ease of use and built to last. Structurally reinforced ribbing provides strength for big trees and a secure fit on the 8 and 13 gallon growth modules. Solid white, non-translucent ABS construction prevents light penetration. The quick access port hole allows for easy root viewing and includes an air inlet / finger holes for hoses to easily pass through. Made in California. Comes standard with all Under Current systems.