Permanent above deck fuel tanks tested to retain pressure and withstand motion.Light, strong and tested tough, these aluminum tanks are the choice of many boat manufacturers. Built to meet the rigorous standards of the US Coast Guard as well as the NMMA. RDS fuel tanks are built of 5052 aluminum alloy and tested for their ability to retain pressure and withstand motion, impact and fire. Before welding, all aluminum parts are bathed in acid to eliminate any contamination that might weaken a weld or create the potential for leakage.Above-Deck Tanks have removablecaps and vented sight gauge units in tank.Key FeaturesSide corners are radius bent, not weldedAll Tanks-have 1/4" NPT pickup, 1 1/2" fill, and 1/2" vent fittingsAdd 3" to height for fittingsAbove-Deck Tanks have vented caps with gauge unitsAll are fitted with plugs for diesel return