Free Plant Growing Guide Free Sandpaper 4-in-1 Multi-Function: This hygrometer can meet your needs to measure soil moisture, Ph, nutrients, and light conditions at the same time. Cost-effective, compared with the traditional single-function soil tester, you only need to buy one, and you can enjoy four services. It can help you gain a complete understanding of your plants Single-probe Design: The single-probe with upgraded material. Compared to traditional dual probes, a single probe can reduce damage to plant roots when inserted into the soil and is a reliable Plant Care Tool Fast Response: You only need to insert the probe deeper than 4 inches into the soil and get test results in seconds (must be greater than 4 inches deep) Patented Design US No.D968976: The patented design of the 90 rotating head allows you to read the dial without bending down and looking down. You can bend the head 1-90 at will. Adjust to the angle that best suits your reading No Batteries Required: easy to store. Great for Garden, Lawn, Farm, Indoor Outdoor Use. If the tester doesn't work, try sanding the tip and pole