Lutron PH-224S PH/ORP Meter

pH, mV, auto Temp. Cal. pH/ORP METER Model : PH-224S * Measurement : pH, mV ( ORP ), Temp. ( via ATC Temp. probe ) * pH : 0 to 14.00 pH * mV ( ORP ) : 1,999 mV. * Temp. ( via ATC Temp. probe ) : 0 to 65 °C, °C/°F. * LCD shows both pH and the temperature. * ATC or manual Temp. compensation. * Auto calibration for pH 4, pH 7 and pH 10. * Hold button, REC button ( Max./Min. button ). * Power : DC 9V battery ( 006P ). * Optional pH electrode : PE-03, PE-11, PE-02, PE-08, PE-21, PE-06HDA, PE-04HD. PE-03K7 * Optional ATC probe, TP-07 * Optional ORP electrode, ORP-14. * Optional pH buffer solution : PH-07, PH-04.