The 2" - 4" First Check Valve Assembly can be used on the Deringer 20 (DC) & 30 (DCDA-II) or the Magnum 20 (DC) for sizes 2", 2 1/2", 3" and 4" and comes pre-assembled from the factory ready for installation.
Note: This check valve assembly is for the 2" - 4" Deringer 20/30 and 2" - 4" Magnum 20 models only. The first and second check valves are not interchangeable.