Top quality, thick-walled seamless polyethylene tanks won't corrode, won't leak, won't bulge or crack under the weight of sewage and won't permeate with sewage odor. Raritan doesn't just sell you a tank! We work with you to determine the best installation for your boat, so you get a tank that's custom made just for you. When your tank is made, all integral fittings are installed at the factory in the locations, number and sizes you need - eliminating the need for fitting relocation kits.