BD-8300 (Ames-Deringer) | 1st Check Poppet Assembly | RP 6X-8 IN | For Deringer 40/50This 6 to 8 Inch First Check Poppet Assembly Can be Used on The Deringer 40(X) And 50(X) Models. They Are Designed For Sizes And Come Pre Assembled From The Factory Ready For Installation. The True Seal(Tm) Check Valve Was Designed to Incorporate a Poppet Only Motion During The Check Stroke And is Used Exclusively on The First Check Assembly on The Deringer RP And Rpda Models. This Design Allows a More Consistent Pressure Loss Across The Check Valve