11 Measurement Units, High Resolution Extech’s PS115 differential pressure manometer is ideal for field, manufacturing or lab/R&D use offering a 15psi range, readings in 11 units and high resolution. The manometer also features a large LCD display with backlighting, data hold, auto power off/disable and zero function for offset correction or measurement. This product is complete with six AAA batteries, 2 connection hoses and a hard carrying case.