The HR-35 Water Caddy is specifically designed for hauling potable drinking water secured on top of a RV, trailer or hay rack. Tanks can also be used to store light chemicals, soaps and detergents.Tanks are manufactured from FDA approved medium-density Food Grade Polyethylene with U.V. inhibitors. The HMHR-48 Hay Rack Tank is also available and can be mounted in series with the HR-35 Hay Rack Tank which adds an additional 48 gallons of capacity or can be used as a separate liquid storage tank. Tank walls are translucent for level viewing. Hay Rack Water Caddy Tanks come with a standard fitting package complete with fill valve/cap and drain with single union ball valve. Tank also includes zip ties and a 10′ 3/4″ garden hose for easy drain-out from top of hay rack.