Digital Differential Manometer, Measures Air And Gas Pressure For Ports P1, P2, And Differential, Range Of +/- 60 inH2O And Full Scale Accuracy Of +/-1.5-Percent, Units Measured: inH2O, bar, oz/in2, psi, mbar, kPa, inHg, mmHg, kg/cm2, ftH20, and cmH2O, Calculates Minimum, Maximum And Average Values, Strong Magnet On Back For Hands-Free Operation, Large LCD Is Backlit, Includes: 6.56' (2 m) x 1/8'' (3 mm) Inside Diameter Silicon Tubing, 3 x AAA Batteries, Pouch & Instruction Manual