2"-4" #1 DC Check Assembly For Model 20/30 SKU: RK-D-4100 $606.00 Login for better price Select Quantity -+ Add to Cart Additional DetailsResourcesManufacturer: Deringer Size: 2 Inch, 2 1/2 Inch, 3 Inch, 4 Inch Product model: 20 / 20G , 30 / 30G Maintenance Manual Deringer 20 2 1/2" - 4" Maintenance Manual Deringer 20G 2 1/2" - 4" Maintenance Manual Deringer 20G 2 1/2" - 4" Spec Sheet Deringer 20G Spec Sheet Deringer 30 How to Maintenance a 2 ½" - 4" Deringer 20 Double Check Backflow Preventer