Harris provides an array of single stage and dual stage regulators. Single stage reduce pressure in a single step to deliver a pressure within a specific range. Regulators designed in this way will show a slight variation in delivery pressure as the cylinder pressure falls during use. For this reason, single stage is best suited for applications where a constant outlet pressure is not critical, where an operator can monitor and readjust pressure, or where inlet pressure is constant. Dual stage perform the same function as single stage regulators. However, delivery pressure remains constant as cylinder pressure decreases, and greater accuracy in pressure control is maintained because the pressure reduction is performed in two steps. Dual stage is recommended for applications requiring a constant outlet pressure over the life of a gas cylinder.