Febco LFFRK 850 886V D 2 1 2 3 Part of the RK LF860 LF866 LF870V 876VST LF876V LF880V LF886V Series Z100F 3NH torsion spring checks and relief torsion spring checks and relief valve This 8 inch N pattern reduced pressure zone assembly backflow preventer helps prevent the reverse flow of fire protection substances and water of non potable quality from being pumped or siphoned into the potable water supply due to backsiphonage and or backpressure in accordance with national plumbing codes and water authority requirements No special tools required for servicing Fits 2 1 2 and 3 inch double check valve assembly and double check detector assembly