The extech hd750 5 psi differential pressure manometer has a 5 psi range and eleven selectable units of measure it shows the max min avg recordings and the relative time stamp the functions included are data hold auto power off and the zero function it has a large lcd display with backlighting to help the user see in low lit areas also this meter has a heavy duty double molded housing and a built in usb port the extech hd700 differential 5 psi pressure manometer comes complete with o