3 in 1: EC and pH are vital measurements in Hydroponic systems. With the 3-in-1 Multifunction Digital Meter you can accurately measure EC, pH and temperature values, accurate to +/- 2% EC, +/- 0.01 pH: and Temp: 0.9F. Comes with a lanyard. Automatic Calibration: Featuring three-point calibration, the meter can automatically identify calibration solutions of pH 4.00, pH 6.86 and pH 9.18. Included 3-pack pH buffer solution (4.00, 6.86 and 9.18). EC calibration solution not included. Recommended to calibrate every 4-6 weeks for accurate measurements. High Accuracy: Highly sensitive probe gives you a full measurement range of 0-19990S/cm EC and 0-14 pH, Rsolution 0.01 pH; 1S/cm; 0.1; 0.1F; Multifunction Digital Meter green backlit display ensures you can read the measuring results under any lighting conditions. Important Hydroponic Measurements: EC measures the level of nutrients in your system and gives you a measurement of the quantity of available nutrients, allowing you to use this information to add nutrients to your desired level. pH is the measure of the acidity of a system and determines how plants and other organisms interact with different nutrients. Multiple Uses: Pocket-sized and multi-functional, the Multifunction Meter is ideal for daily use inluding hydroponic systems, drinking water, saltwater pools, hot tubs, spas, aquariums and home brewing. Auto shut off: 5 Minutes. It is waterproof which means you won't have to worry about dropping it in water or other liquids.