HDPE is superior to metal in breakage and corrosion resistance. The 4.5"Dia. tank opening makes filling and cleaning easier and safer. Equipped with Viton seals and gaskets for safe use with a wide variety of chemicals. The extra-large, heavy-duty pump pressurizes the tank with less effort than other sprayers. A pump handle and piston provide superior comfort and durability. An automatic pressure-relief valve releases at 45 psi to avoid dangerous overinflation. It also allows for a release of stored pressure without costly spray-outs or difficult tank openings. Its extra-long 4' clear reinforced high-pressure hose is tough yet extremely flexible. The 28" wand and shut-off valve are exceptionally durable and provide extended reach.