Sony ICD-PX470 Digital Voice Recorder is comes with 4GB memory which gives you a max recording time of 59h35m when recording in stereo at MP3 128kbps and also expand your memory capacity with a micro SD card for up to 32GB of additional memory – equivalent to over 536 hours (Micro SD 32GB 、MP3 128kbps) of recording time.. This Voice recorder has USB direct connection for quick file transfer, which is helps you to transferring files to or from your computer is fast and convenient. Just plug the ICD-PX470 straight into a free USB port for an immediate connection and no USB cable needed. In this voice recorder, the recordings are marked by date, so you can easily find which ones were made on a specific day. Bring up the calendar to browse through days and find the recording you’re looking for. This voice recorder has Low cut filter to eliminates unwanted noise. In this voice recorder, the Auto Voice Recording reduces background noise and it's adjustable microphone range for clearer voices. This Sony voice recorder also built-in mic at MP3 192/128kbps, the supplied AAA battery will last for up to 55 hours. That’s over two full days of non-stop recording in between battery changes – perfect for recording at long conferences and events