The external antenna Salus 08RFA is a device used to increase the transmission power of central controls to other devices within an IT600 system. Its use is necessary when the central control is installed inside a metal box, where the data transmission range is affected by the metal materials of the box. The external antenna Salus 08RFA is used together with the central control Salus KL08RF, boosting its signal to the thermostats of the IT600 series, specifically to the wireless thermostats VS10RF or VS20RF.