GNC P530 piston pump outlet chamber. Reference #3 on the parts diagram.P530 Microswitch Outlet Assembly. Includes: 42-531-75 Microswitch,43-531-200 Microswitch Regulator, 42-531-75 Microswitch Outlet and (2) 42-531-74 BoltsP530 24v BOSS Regulator with Microswitch 43-531-365SKU: 43-531-365 $405.31 Regular Price$344.51Sale PriceExcluding Sales TaxQuantity*Add to CartBuy Now