Product Description SmartTote Tank - 18 Gallon is Thetford's new, premium portable waste tanks which bring it all together in a sleek, easy-to-use design. The innovative design saves time, effort and hassle. This ingenious tank is in a class by itself. Completely self-contained so there are no required accessories to buy or parts to store. Each model has up to 20 percent more capacity than competitive models for fewer fill-ups - saving time and effort. Self storing sewer hose stays connected at bottom of tank. Cradle pivots, hose extends for quick, clean hookup. Bayonet cap prevents spills, just pull out, connect to fill or empty. Level Gauge/Valve stops flow when tank is full to prevent messy over-filling. No heavy lifting - use the convenient, included tow handle (on LX models) to easily pull your SmartTote from RV to evacuation. LX Models are the top of the line and include these super-convenient features, four wheels for easy maneuvering, tow handle for easy towing (even hooks to ball hitch), stows flat for storage, rinse hose, convenient and easy to store. PermaStore and AutoStop not available on 12 gallon model.