ModbusBox is a product developed by IOTBITS that allows the integration of industrial controllers and devices supporting Modbus RTU into the IoT world. ModbusBox is easy to use thanks to its embedded web configuration portal accessible via Wi-Fi it can be set to work as access point mode (AP), and in client mode when its connected to your local WIFI network. ModbusBox is capable to read data registers from Modbus slaves (maximum 4) and send data periodically to cloud or local network IOT services using the very popular MQTT protocol. Data is serialized using JSON format, so it's very easy to parse the information on the IOT server. Slaves variables can be processed and displayed in dashboards by many open source IOT platforms like Node-red, InfluxDB & Grafana, Ubidots educational and its pay platform which is very powerfully and easy to use. ModbusBox has been tested and optimized to be connected to Variable frequency drives, but it also can be setup to be connected to other devices like PLC's, power energy meters and many different industrial products.\ ModbusBox advanced version can be easily customized to add new Slaves and functions, this feature is very powerful for those wanting to try ModbusBox with other devices as long as the user has a clear picture of the devices Modbus register addresses.