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 HT636ED Holding Tank from Icon features a center end drain and a 32 gallon holding capacity. The dimensions of this tank are 57" x 24.5" x 7". Comes with 3" spigot fittings and four level sensors installed on the tank.