Features: 1. Power switch/record switch 2. Volume up/next track key 3. Volume down/MP3 music conversion key 4. 3.5mm jack 5. Work indicator lamp 6. Up to 48 hours of continuous recording on 4GB capacity 7. Recorded files in WMA/MP3 format 8. High capacity storage 9. Built-in rechargeable lithium battery 10. USB storage write protection 11. One-touch recording and high-quality audio recording 12. High-sensitivity built-in microphone for clear recording 13. Supports recording from external audio sources 14. Functions as a driver-free USB flash drive 15. MP3 playback function Specifications: Battery life: Up to 3-5 hours of continuous recording Playback time: Up to 3-5 hours Recording format: WAV Music playback formats: MP3, WMA, WAV Sampling frequency: 48kHz Bit rate: 192kbps Dimensions: 47 x 19 x 7mm Notes: Due to high recording quality and advanced parameters, file sizes may be large. It is recommended to regularly transfer and save recorded files. This device includes an automatic reset function. Always save current files before connecting to a computer. Package includes: 1 x Voice recorder (8/16/32GB) 1 x User manual