Sony ICD PX333 4GB Digital Voice Recorder - Certified Refurbished 4GB Internal Flash Memory, Requires 2 AAA Batteries microSD Expansion Memory Slot, Records Mono MP3s Intelligent Noise Cut, A-B Repeat Function Track Mark Function, USB Cable to Transfer Files to Mac/PC System Requirements: Windows XP (SP3), Vista (SP2), 7, 8 Mac OS X 10.3.9 to 10.8