PAE Reverse Osmosis RO-132 4 Gallon Storage TankPre-pressurized bladder tanks. Pressured bladder tanks have several advantages over atmospheric tanks. Pressurized tanks do not require any delivery pump and are less likely to have microbial contamination versus atmospheric tanks. Volume is 4 gallons. Capacity is approximately 3.2 Gallons. PAE's reverse osmosis RO-132 works great as a replacement tank for almost any RO system including EcoWater, Culligan, Rainsoft, Watts Premier and any other RO system on the market. Specifications: Tank Volume Manufacturer Part #: Diameter x Height Connector 4 Gallons RO-132 � 11" x 13" 1/4"