Moeller permanent tanks are favored by quality boat builders. Cross-linked rotationally molded polyethylene fuel tanks are UV stabilized and impervious to corrosion and ethanol-enhanced fuel. They meet all ABYC, NMMA and U.S. Coast Guard regulations. They’re equipped with an electrical fuel sending unit for use with a dash-mounted gauge. Measurements do not include fittings. Add 2 1/2" to height for fill neck. Allow for hydrocarbon swelling that adds about 3% to measurements in all directions.