The Vertex is a fully enclosed soil sensor with built-in telemetry and power, so no extra device is needed. It measures soil moisture (VWC) and EC (salinity) at three depths, and temperature at the top two. It also calculates moisture every 10 cm from 20 to 66 cm. The spiral design is meant to prevent preferential water flow along the sensor. You follow the data remotely in the app and use it for irrigation, disease management and nutrient monitoring. Quick to install.