
This had been placed on extended back order by the manufacturer. The recommended replacement parts are: 2-inch diverter 11-4000GRY & 2-in to 1-in adapter 437-249.
HydroAir/Balboa - Diverter Valve, Hydro-Air/BWG Hydroflow, 1"s, 2 Port, Gray - 11-4020-GR
HydroAir "Hydroflow" 3-Way Valve Available in 2" and 1" sizes topside mounted easy to turn, allows for zoning to banks of jets and permits variable flow to different areas.
Hole size for 2" valve is 3-3/16". Hole size for 1" valve is 2-1/16"