AXIS T8355 Digital Microphone is a high-performance. discreet microphone specially designed for best surveillance in large areas. First microphone with an S/PDIF output carrying digital audio signals between the microphone and network product. Thanks to the digital format with lossless transfer of audio signals. electromagnetic immunity is achieved making it ideal for situations where up to 100 m (328 ft) long cables are required. This hemispherical microphone collects sound from every direction. and the quality of the recording is vastly superior to that of the network product’s internal microphone. Powered by the network product. no external supply needed.