Coverage expander for MIW systems via radio to improve the covering distance. Occupy an output module direction in the loop and requires an extern power supply of 24VDC 25mA from a certified source in accordance with EN54-4 standard. Provide a double orthogonal antenna to guarantee communications and RS232 port for PC programmation. Can be associated with a maximum of 7 expenders for each MIW-INT interface, 5 are continued connected and up to a maximum of 3 connected to an other MIW-EXP.