Features: 1. pH measurement range: 3.5-8 Ph (3.5-6.5 acid, 7 medium, 7-8 alkali) 2. Humidity measurement range: 1-10 (1-3 dry, 4-7 medium, 8-10 wet)3. Illumination: 0-2000 lux (0-200 low, 200-500 low, 500-1000 medium, 1000-2000 high) Color: green material: plastic Dimensions: Probe length: 21cm Copper probe diameter: 4.8mm Aluminum probe diameter: 5.1mm Distance between two probes: 1.2cm Instructions: When measuring the pH and humidity of the soil, first insert the probe into the soil as deep as possible, leaving about 1 cm above the probe. Move the button on the pen to MOIST, MOIST is the moisture button, the corresponding table is MOIST, DRY is dry, WET is wet, the value 1-3 (red part) indicates that water is needed, 4-7 (green part) It is appropriate, please adjust the watering time according to the species of the plant, 8-10 (the blue part) means it is too wet. Move the button on the pen to PH, PH is the pH key, the corresponding table is 8-3.5, ALKALINE is alkali, ACDIC is acid, and the value 7 is basically neutral. The smaller the number, the greater the acidity. Please refer to the plant Adjust the pH of the soil. The LIGHT key is the illuminance, the measurement range is 0-2000 lumens, the larger the value, the stronger the light, please decide whether you need shade according to the species of the plant. When using, pay attention not to touch the stone when inserting the electrode, do not use too much force, or it will easily damage the electrode. Wash the electrode after use.