Sony ICD-BX140 4GB Digital Voice Recorder Built-in 4 GB flash memory. Automatic record level settings Up to 4,175 Hours of maximum recording time. Low Cut Filter for reduced wind effect Mono microphone for 75 Hz15 kHz audio response Features built in monaural microphone. Battery life for recording mp3 128 kbps is 28 hours. Battery life for recording mp3 192 kbps is 26 hours Voice Activated Recording for hands-free recording. Noise Cut mode helps provide clear speech playback In the box: IC Recorder, LR03 (size AAA) alkaline batteries (2), Quick Start Guide