General Tools GLMM300 Soil pH Tester The General Tools and Instruments GLMM300 Soil pH Tester instantly reads soil or compost acidity Knowing the pH levels of soil can help you determine the health and wellness of your plants Use this tool in the field, garden or even inside the home on interior plants; no batteries are required to use The instrument comes with a plant pH chart that helps to interpret and understand the read outs Comes backed with a 1-Year Limited Warranty along with General Tools design and quality