Achieve professional results at an economical price! The WD-35413-20 microprocessor-based Eutech pH6+ meter gives you high accuracy and reliability. Use this meter to take pH, mV and temperature measurements. The millivolt readout lets you take ORP readings. The WD3541320 Meter includes a protective rubber boot that also acts as a meter stand, with a NIST calibration certificate from INNOCAL.