Battery is no need.Could test soil pH soil fertility.Suggest to use indoors or outdoors.convenient to use, simple to operate, solid quality.Accurate results.Specifications:Material: PlasticSoil PH Measurement Range: About 2.5 - 10.0 pHAccuracy: About ±0.25 pH(20℃)±0.2 pH (Suitable for farm or education experiments)Working Temperature: About 0 - 50°C(32-122°F)Calibration: Manual point 1Measurements: About 11cm/4.33" X 6cm/2.36"Length of Probe: About 6cm/2.36" (Include telescopic rope)Notes:1. Soil pH value is a very important factor for the quality of crops.2. Most of crops cannot survive in too acid or too alkaline soil.3. Get the right pH reading for your Crop is very important.Using Method:1. Measuring soil pH, as far as possible to probe deeply into the earth and probe the upper portion for about 1 cm.2. On the table is 2.5-9 numerical, numerical 7 basic is neutral, the smaller the number shows that the greater the acidity, please adjust soil pH value according to plant varieties.4. Please pay attention that insert electrodes without touching the stone, not too hard, otherwise easy to damage the electrode, clean electrode after use.Packing list:1 * pH MeterEasy to use and provide fast measurements