The stereo 192kHz option includes a two-channel 192kHz 16-bit sample rate card and one SMX-US weatherproof ultrasonic microphone. With two channels, it's like having two bat detectors in one. A second ultrasonic microphone extended on a cable can be used to monitor bats up to 100 meters away. For example, one microphone could be mounted at nacelle height and another near ground level to meet the requirements of many wind farm pre-construction surveys. Alternatively, the second channel could also be used with a conventional SMX-II acoustic microphone to record birds, frogs, and other wildlife either simultaneously or at different scheduled times with bat monitoring. Bat echolocation calls up to 96kHz can be recorded, sufficient for monitoring nearly all species present in North America. Play them back slowed down 16x to get the audible sound. The mono option for up to 384khz. http://www.wildlifeacoustics.com/sm2_bats.php#audiolink1 song meter user manual: http://www.wildlifeacoustics.com/downloads/SM.pdf how to record/playback booklet