Ideal for use with RO water for spot-free rinse systems or for Potable water storage. Constructed of one-piece, seamless polyethylene. Self-locking covers are standard. 850 gallon tanks feature (1) 24" manhole with lid. 1150 gallon tank features (2) 24" manholes with lids. 1200 & 1700 gallon tanks feature (2) 20" manholes with lids.