Features: 2 chamber dual diaphragm Positive displacement On demand operation Chemical resistant polypropylene body 30 to 60 PSI (2.1 - 4.1 bar) SHURflo's 166 Air Operated Demand Pumps employ a dual diaphragm design, with a patented fast action switching mechanism allowing for consistent flow and pressure. They are built for the toughest pumping applications and are available in a variety of elastomers that allow them to be compatible with mild caustic or acidic fluids. Ideal for chemical transfer, injection and spraying. Model Description 166-200-36 Viton® Air Pump 0.6 GPM (2.3 l/min) continuous duty Viton® valves and diaphragm 166-200-46 Buna Air Pump 0.6 GPM (2.3 l/min) continuous duty Buna valves and diaphragm 166-200-56 EPDM Air Pump 0.6 GPM (2.3 l/min) continuous duty EPDM valves and diaphragm 166-200-57 Santoprene® Air Pump 0.6 GPM (2.3 l/min) continuous duty Santoprene® valves and diaphragm