Check the listing for details. HM Digital Hydromaster 500 - Continuous pH/TDS/EC/Temp meter. Condition: New. Listed at 299.50 USD. HM-500 HydroMaster: EC/TDS, pH, Temp Continuous MonitorThe HM-500 is the most versatile continuous monitor indicating EC/TDS, pH, and Temp providing accurate, stable readings the user can rely on. With its rechargeable battery this unit is portable or can be wall mounted.. To make is even more user friendly, it comes equipped with touch screen, high and low alarm set points, and recorded readings. It is ideal for hydroponics and other applications such as lab, pools, aquariums etc.FeaturesContinuous pH/EC/TDS/Temp MonitorRechargeable batteryRF ResistantPortable/Wall Mount/BenchtopData Storage: Up to 20 measurement readingsAuto Shut-Off: After 5 minutesAlarm: Adjustable High & Low Set Point and on/offDisplay: LCD Touch-Type Screen with Auto Back lightingProbe: ABS with Platinum electrodes for EC / Single Junction pH SensorThree Year Warranty Power Source: AC 110 V – 220V / Rechargeable Lithium Ion BatteryFunction Environment: 0 – 50°C (0-122°C) / RH 80 % (EC Probe: 0 – 80°C)Sensor Cable: 24-inch shielded Coaxial CableDimensions: About 8 x 4 x 1.5 inchesWeight: 15.2 ounces for body / 5 ounces for two probes (without case)