The 3-in-1 soil tester allows you to scientifically measure soil light, moisture and pH. Our soil test kits help you make healthier plants (cannot be used to measure water pH) Easy to use: No need for batteries, just insert the probe into the measured ground (at least 10cm deep) to get accurate data. If your plants are very dry, the soil tester needle will not spin. Therefore, your plants should be watered now! Super Durable: The metal probe used for PH value is more durable than the glass probe (please note that the metal probe needs to be cleaned to keep the probe dry and clean). [APPLICABLE FOR INDOOR AND OUTDOOR]: This 3-in-1 soil tester is a great tool for managing your garden, flowers, plants, vegetables, shrubs. Scientifically True: Very easy to accurately read humidity, pH and light levels.