Features: Operating voltage: 3V Operating current: 10uA Battery: 1 3V CR2032 button battery (not included) Rated power: 0.03W Measuring range: 5% Red light: lack of water. Green light: Good for humidification. Blu-ray: Too much water Step 1: Before first use, please open the top cover and pull out the inner plastic panel. Step 2: Insert the soil tester sensor into the soil. Step 3: Click the power button. Step 4: Wait a moment and use a light color to see if there is more or less moisture. Note:1. Please allow a little error due to manual measurement. Please make sure you don't mind before bidding.2. Color may vary due to different monitors, please understand. Note:Hello, please pay attention to your delivery address when purchasing products. If your delivery information (such as name, street, house number, doorbell/mailbox without name, etc.) is incorrect, the order will not be delivered correctly.)