2-stage or dual stage propane regulators controls and regularizes the pressure of propane flowing from the service line to the appliance - at a safe level suitable for domestic use. They are approved for use in various portable applications and outdoor cooking appliances utilizing low pressure. They have high and low pressure 1/8" NPT ports, an integral second stage drip lip vent and optional standard or 90 degree vent locations. GR-291H regulators are ideally suited for RV, outdoor appliances, cabins, seasonal homes, gas fire places, water heaters, ranges or other moderate to low demand domestic home installations. GR-291L are intended for low BTU demands that still require 2-stage regulation. GR-291 series meet UL, RVIA and NFPA requirements.