The PRD28 manifold mount two-stage non-relieving diaphragm regulator sets an industry standard for both miniaturization and light weight. It weighs approximately 52 grams in brass. It accurately reduces high-pressure inputs (up to 500 psi) down to 0 to 20 psi (and is especially suited to low pressure regulation such as 1/2 psi.) with minimal droop or rise even with wide swings in inlet pressure. The PRD28 two-stage diaphragm regulator is an excellent choice if the inlet pressure will decay over time such as with hydrogen storage tanks commonly used in hydrogen fuel cell applications. The inlet is a 5/16-24 UNF external thread and the outlet port is through a 0.094" diameter hole at the base of the regulator body. Applications include hydrogen fuel cells, medical equipment, instruments, laboratory equipment, ink jet print engines, and semiconductor manufacturing equipment.