2-Pack comes with 2 separate packages: Reliable and Accurate-Sensing probe ensures accurate and instant testing results, matching for both indoor or outdoor use. EASY TO READ: Large dial, including ten scales, Plug and read. HOW TO USE -- No batteries needed, Indoor or outdoor use. Simply insert the probes into the soil about 3-4 inches, and you'll get your reading Ideal tool for indoor/outdoor plants, help your plants grow healthy and strong. Less damage: Single probe, less damage to the roots, doesn't dig up too much soil after test. IMPORTANT TIPs --1, Do not use it to test water. Do not touch the stone or hard rock soil, if the soil is too hard and dry, easy to damage the probes. 2. Never use it to test liquid. Designed for testing soil ONLY. 3. After use, please wipe clean the probe.