4 wheel， flow meter kit， operates at 6 to 40 gpm， 23 to 151 lpm， with accuracy of +/- 2%， easy reset register indicates product use up to 999.9 gallons or 9，999 liters， master totalizer registers up to 9，999，999 gallons/liters， large， easy to read numbers， measure fluids at temperatures up to 150 degrees Fahrenheit， 63 degrees Celsius， pressures up to 50 psi， 3.4 bars， quick reset knob， flexible flow ports can be positioned vertically or horizontally， ul/cul listed.