This nozzle, built on the Master Stream body, is a fixed constant flow nozzle. It is factory preset at the customer's specified K-factor 50 to 105 (1000 gpm (4000 l/min) max ). 2.5" NH (64mm) rocker lug swivel coupling is standard. 3.0" NH (75mm) or 3.5" NH (90mm) coupling is optional. Flow and pressure are laser engraved on the baffle. For use on TFT RC monitors only.