The TEFL-RH, manufactured by Produal, is a series of wireless room temperature and humidity sensors that are made to detect temperature and humidity of indoor spaces. They work in the frequency range of 868.30MHz and they are powered by lithium batter.
There are two ways when it comes to the communication between the TEFL room devices and the FLTA base station. Each of the sensor is configured at the commisioning phase with its own sensor identification number and the base station identification number.