The #1663 Soil Test Kit from Environmental Concepts is a liquid based testing kit which is great for hobbyists, classrooms and professionals. In contains all components needed for a total of 80 tests. 20 each for soil pH, Nitrogen, Phosphorus and Potash. Detailed instructions are included along with extensive guidelines for altering soil and using the best plants for your soil environment. From Environmental Concepts, makers of high quality soil testing products for over 40 years.