Specification Brand : Pres Air Trol BulletPoint : Pressure Switch, PresAirTrol, Thd Stem, 21A, 1/8"mpt, SPDT BulletPoint1 : Package Dimensions: 4.08" (L) x 8.0" (W) x 11.0" (H) BulletPoint2 : Product Type: Food Service Supply BulletPoint3 : Package Quantity: 1 BulletPoint4 : Country Of Origin: United States BulletPoint5 : Normally open pneumatic switch, long service life and not easy to damage CircuitType : 2-way Color : Black ConnectivityProtocol : X-10 ConnectorType : Threaded ControlMethod : touch CurrentRating : 21 amps CustomerPackageType : Standard Packaging ExteriorFinish : Stainless Steel ExternallyAssignedProductIdentifier1 : 758614141076 ExternallyAssignedProductIdentifier2 : 0758614141076 IncludedComponents : Replacement Part InternationalProtectionRating : 0.125 inch ItemDisplayDimensions_Length : 2.4 inches ItemDisplayWeight : 1 pounds ItemName : Presair Pressure Switch, SPDT, 1/8in Thread, 1-5 PSI Adjustable, PM11120E PM11120A ItemPackageDimensions_Height : 1.7 inches ItemPackageDimensions_Length : 2.4 inches ItemPackageDimensions_Width : 2.1 inches ItemPackageQuantity : 1 ItemTypeKeyword : electronic-pressure-switches Manufacturer : Tecmark Material : Plastic ModelNumber : PM11120A MountingType : Panel Mount NumberOfBoxes : 1 NumberOfItems : 1 NumberOfPorts : 2 NumberOfPositions : 3 OperatingVoltage : 120 volts OperationMode : ON-OFF PartNumber : PM11120A ProductDescription : Pres-Air-Trol 21 amp pressure switch PM11120E has 1/8 in plastic threads (measuring 3/8"" OD) for connection to heater or header or water hose, and three wire terminals for common, NC and NO wires. Adjustable pressure switch is Normally Open and comes factory set at 1 psi but can be adjusted with a hex key, with a clean filter, to meet a variety of system pressures, as low as 1 psi up to 5 psi. Made in the USA by PresAir. Pressure switches are used on spa, tub and bath heaters to measure the amount of water pressure inside of the heater, as an approximation of water flow. Pressure switches are safety devices intended to prevent heater damage and overheated water hazards. If your pressure switch is causing the heater to shut down, look for causes of low flow in and out of the heater, and remove the spa filter temporarily to improve flow. Pressure switches do fail eventually (which is why sell replacements), but first assume a flow problem, and not a switch problem. ProductSiteLaunchDate : 2016-01-12T06:59:16.069Z SpecificationMet : IP54, RoHS SupplierDeclaredDgHzRegulation : not_applicable SwitchType : Pressure Switch TerminalType : Spdt UnitCount : 1 UnspscCode : 39122200 ValveType : Globe Valve