TDS – PPM Meter, Range: 0 1990 ppm With Automatic Temperature Compensation (ATC) and 1 Point Manual Calibration, Supplied with MA811D/1 TDS Probe, 110 Volt Power Supply, Unit Mounting Kit, Probe Holder, a 20 ml – 1382 ppm Sachet Calibration Solution and Screwdriver for Calibration.