These have a PTFE seal, food grade EPDM o-ring, 316SS body, and nominal pressure rating 145psi (liquids only, including beverages and some solvents or chemicals) for filling totes, containers, sampling, admixing, etc. N5195 automatic will register the change in flow pressure and stop automatically, whereas the N5194 has a manual trigger. N5195 automatic requires a min pressure of approx 16 psi at the nozzle to shut off properly, and it can only handle light fluids or media (not thicker than diesel as an example) due to its internal workings. N5194 manual nozzle can handle thicker fluids (such as the thickness of paint as an example).