Icon holding tanks are thermoformed of high impact ABS plastic. All seams are solvent welded and have a 1-1/4" mounting flange around the perimeter for easy installation. The HT330RE Holding Tank from Icon features a recessed drain and a 36 gallon holding capacity. The dimensions of this tank are 58.5" x 26.5" x 10". Comes with 3" spigot fittings and four level sensors installed on the tank.