Ideal for plant and field uses. Protective carrying case organizes meter and materials. Includes everything you need for convenient calibration. Calibration standards are made with NIST traceable materials.Each kit contains TDS Singles calibration pouches (two each of 447 µS, 1413 µS, 2764 µS, 15,000 µS, and rinse water); sample jar; and screwdriver - all in a foam-lined, hard shell carrying case with room for your TDSTestr (order Tester separately).TDS Singles are handy, single use pouches that each contain 20 ml of fresh calibration solution.Includes: MSDS. Accuracy is ±1% at 25°C.