Part Number: 8.712-568.0 Cross Reference Part Number(s): 462235, 87125680 Manufacturer’s Part Number (MPN): AR20399 This 8.712-568.0 Gymatic 3B pressure regulating unloader is manufactured for use with Annovi Reverberi (AR) Pumps. The internal bypass eliminates the need for an external bypass hose and releases pressure within the pump head when the trigger gun is released, to protect the pump from over pressurization. This pump unloader valve includes a 1.8mm Adjustable Chemical Injector and is rated for pressures up to 3650 PSI and 3 GPM to 5.5 GPM.