Description Scientifically accurate: Easy & accurately to read moisture, pH and light levels, promotes healthy plants. Moisture Range:1-10 (1-3 DRY, 4-7 NOR, 8-10 WET); Relative Light:0-2000 Lux (0-200 LOW, 200-500LOW+, 500-1000 NOR 1000-2000 HGH); PH Range:3.5-8 PH (3.5-6.5 ACID, 7 NOR, 7-8 ALKALI). Just need plug and read. It's very easy to use! If the plants are very dry, the Soil Meter's Pointer will does not rotate! It means that your plants need to water right now. Compact for indoor or outdoor use: Know when to water, adjust PH, or change lighting for your garden, flowers, plants both indoor and outdoor. Measures moisture at root level. No battery required, simple and convenient to use. Simply insert the meter into the soil, switch to the setting you want to measure and read the scale. PH Range:3.5-8.0 (3.5-6.5:ACIDIC, 7:NOR, 7-8:ALKALINE). Moisture Range:1-10 (1-3:DRY, 4-7:NOR, 8-10:WET). Light Range:0-2000. To avoid damaging the electrode, do not use in soil with stones and insert forciblyplease clean the electrode after each use. Package Include: 1 x 3-in-1 Soil Meter Note: 1. Please allow 2-3% difference due to manual measurement. 2. Besides different computers display colors differently, the color of the actual item may vary slightly from the below images, thanks for your understanding(1 inch = 2.54 cm)