H4n Pro is a voice recorder which has a 4 channel mode with recording up to 68 hours of mp3 at 128 kbps stereo track with a 4GB SDHC. Advanced X/Y microphones, incredibly natural-sounding preamps, and a super-low noise floor, you can record everything from the Indy 500 to the fluttering of a hummingbird with extraordinary realism.