Features: 1. Power switch/record switch. 2. Volume plus/next track key. 3. Volume minus/MP3 music conversion key. 4. 3.5mm jack. 5. Work indicator lamp. 6. Lasts approximately 48 hours for 4GB during continuous recording. 7. Recorded files in WMA/MP3 format. 8. High capacity. 9. Built-in rechargeable lithium battery. 10. USB storage write protection. 11. One-touch recording and high-quality recording. 12. Recording via high-grade built-in microphone. 13. Records audio from phone calls. 14. Functions as a driver-free USB flash drive. 15. MP3 playback function. Specifications: Battery life: lasts approximately 3-5 hours during continuous recording. Lasts approximately 3-5 hours during continuous playback. Recording format: WAV. Music format: MP3/WMA/WAV. Sampling frequency: 48kHz. Bit rate: 192kbps. Dimensions: 47 x 19 x 7mm. Note: Due to the high recording quality and advanced parameters, the recorded files are relatively large. Please transfer and save files promptly. Warning: This device features an intelligent reset system. Please save any ongoing recordings before connecting to a computer. Package includes: 1 x 8/16/32GB voice recorder 1 x user manual