Independent electrochemical and infrared technology for the detection of toxic gases and O2. Independent functioning, does not require central. There is a new independent version with RS485 addressable communication compatible with DURGAS™ centrals (from the v04 DURGAS™ version). Provided with a 16 X 2 lines display, backlit and three buttons. Allows to programme the prealarm level, alarm level, initial state of manoeuvre output, type of manual or automatic rearming, rearming timing, activation or non activation of the internal acoustics and possibility of inhibiting the sensor to avoid inappropriate manoeuvres in case of breakout.