The Large Standard Flow Stem & Disc Assembly is engineered to restore smooth, dependable operation to FIMCO indexing valves. Designed for irrigation systems running at flow rates above 10 GPM, it delivers consistent zone indexing to keep water distribution efficient. This replacement assembly fits standard-size FIMCO valves that use an eight-screw top plate, making it an ideal drop-in solution for 3000-series and higher valves.