Internal memory / maximum recording time (LP mode): -WS-811: 2GB / over 500 hours -Recording formats: WMA, MP3 and PCM (WS-811 without PCM) -microSD Card slot for external memory of up to 32GB -Direct USB connection / USB stick functionality -High quality stereo microphone -Range adjustable Zoom Microphone function (WS-813) -High S/N ratio -Voice Filter (WS-811) -Low-cut filter (rec.) and noise cancel playback function -Scene select -Calendar Search function -Voice Playback function to play back only the parts with voices -Voice activated recording mode for hands-free use (VCVA) -Voice sync function -Fast playback speed (2x for WS-811) -mp3/WMA music player -Up to 99 index marks -5 folders for file storage, 200 messages per folder -Large backlight LCD -Long battery life: Up to 27 hours (with 1 AAA-type alkaline battery in LP mode) -Internal battery charge function Dimensions (HxWxD): 100.2 x 40 x 14.8mm Weight: 57g (incl. battery)