HM-100 Includes Only: Monitor Power cable PH 4 & 7 calibration solutions PH storage solution The HM-100 is a pH/EC/TDS/Temp monitor ideal for all water quality testing, hydroponics, water purification applications, wastewater regulation, aquaculture, colloidal silver, labs & scientific testing, pools & spas, ecology testing, boilers & cooling towers, water treatment and more. Features: Measures Potential Hydrogen (pH), Electrical Conductivity (EC), Total Dissolved Solids (TDS), Salinity and Temperature Four scales: pH, mS, ppm 0.5 (NaCl) Scale & 0.7 (442) Scale Automatic Temperature Compensation (ATC) using three temperature coefficients Digital Calibration (push button) to any point within the meter's range Data-hold function (Max. 6 data values) Large and easy-to-read LCD Screen Displays 3 parameters (pH/EC or TDS/Temp) simultaneously. Replaceable Sensors (model SP-C2 for Conductivity, SP-P5 for pH) Factory Calibrated (pH/EC/TDS)