General Tools DM8215 Deluxe Digital Manometer, 0-15 psi Digital display of gauge or differential pressure Display unit options are psi, inHO, bar, mmHg, ozin, kgcm, kPa, ftHO, inHg, cmHO and mbar Minimum/Maximum memory and data hold RS-232 output jack; optional PC data logging kit includes RS-232 to USB adaptor Auto Power Off; can be disabled for data logging