.020 Flow control disk fits in place of a jet but can be installed in line between you strainer and strainer body cap to control flow rates. On the Prochem Everest it is used to keep the water in motion back to the mixing water box off the heat exchanger. OEM Association: 790836 A common part in the Sapphire Scientific Hoss 700 rotary power wand. Seen here as the silver disk in photo. Please note that non of the brass parts are included with this part number. Each part needs to be purchase individually. Designed to mount between NA0825 strainer and strainer adapter NA0804. See chart below. Same water flow as an 3.5 nozzle/ jet or 3.5 gallons per minute at 4000 psi. Options: