Pre-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. Holds 2 Gallon. NSF 58 Certified. Specifications: Size Item No. Diameter x Height Connector 2.0 Gallons TK-PRO-2-SS-W12 Ø 8" x 13" 1/2"