When sourcing fire jet spray nozzles, you must prioritize material durability and hydraulic performance. Look for nozzles made from corrosion-resistant materials such as heavy-duty brass, aluminum alloy, or stainless steel to ensure longevity in harsh environments. Key technical parameters include the working pressure (typically 0.2-1.6 MPa), the flow rate (measured in L/min), and the effective throw range. For versatile firefighting, ensure the nozzle supports both straight stream (jet) and spray (fog) patterns, with a smooth transition mechanism to handle different fire classes effectively.