The Triplett Model DPR305 Differential Pressure Manometer measure gauge and differential pressure to plus minus 5 PSI. Use 1 input to measure the gauge pressure of a single source. Use both inputs to measure the differential pressure between 2 points of a single source or between 2 sources revealing which input has the higher pressure and the difference between them. Measurements are viewed on the large backlit LCD display in 11 units of measure. Mininum/Maximum/Average records highest, lowest and average readings with relative time stamp. Data Hold momentarily freezes the displayed reading for easy viewing. It features convenient quick.disconnect fittings, zero adjust, offset function, and auto power off with disable. Includes 3 AAA batteries, USB cable (for power only), sample tubing, and pouch case. 1-year warranty.