Brass Spigot containing 2 x OV20 Check valve Cartridges and 25 x 2.5 mm Nitrile O-ring, for use with the SPED15 and SPWP15 Standpipe Assembly. The low loss Double Check Valve provides Fluid Category 3 protection and affords a good flow of water even in low pressure areas by virtue of high-flow cartridges.