Tough extra large tanks. 2" flat flange assures maximum strength. Withstands constant operating temp to 140°F, intermittent service to 160°F . Wall thickness approx. 5/16". U.V. Stabilized. Translucent for liquid level viewing.. ID dimensions are approx.It is recommended tanks greater than 18" H or at elevated temperatures be simply braced with angle iron or 2x4's for full side support. Not for fuels or oils.Covers are loose fitting. Made of medium density polyethylene.