Aprea Instruments SX610 pH Pen Tester is designed for reliable measuring performance with a single-button easy operation in a mini body. A cost-effective choice for your general-purpose pH testing, including hydroponics, aquaculture, water treatment, pools & spas, beverage making, education, etc. The 8mm slim pH probe is replaceable and suitable for test tube measuring. Easy 1-3 point Auto. Calibration (7. 00, 4. 00, 10. 01) and 0 to 60˚C Auto. Temperature Compensation (ATC), 0. 01 pH/0. 6˚C accuracy with 0 to 14. 00 pH measuring range. Intelligent functions: switch from ˚F to ˚C, automatic power-off, low battery alarm, pH probe invalidation reminder (reminds you to replace the probe for reliable performance). The meter comes with a complete kit of premixed calibration solutions (7. 00, 4. 00, 10. 01), storage solution (3M KCL), CR2032 lithium batteries all in a small pocket carrying case. IP57 waterproof and dustproof floats on water, so you don’t have to worry if it falls in water by accident. The product is CE and RoHS certified, and is manufactured under an ISO 9001: 2015 certified quality system. Do NOT store the probe in distilled water or deionized water since it will cause damage to the electrode. Only use distilled water for rinsing the pH probe.