no its psi that the srcue a justs .on the head of the pump is a small srcue holding the cover on under neth is the a juster ,iv not tuched mine ,but iv got a red hat pump looks the same pump and ajusted that one and iv got less flow on it by ajusting it its 80 psi and 4l minet , iv not checed the flow rate now but its def less flow .i run it thow 100m microw ,dont nowe if it wood be dif with sort hose or biger bor hose ,