Sherwood Magnum Regulators: "Dry Air Demand" 1st stage, sealed for diminished wear, great reliability Environmentally Sealed First Stage Work horse of the industry Used by rental departments throughout the industry because of it's reliability! Economic for the consumer I really like these regulators - they are easy on your pocket book because they require minimal maintenace - I save about $100 per year with mine. John, Owner Call us at 206-298-6998 to make an inquiry.