S23 Black Mini Key Ring Shape USB Flash Drive MP3 Player Noise Reduction Audio Recorder16GB (About 192 hours) Item Type: USB Flash Disk Material: Zinc Alloy Colour: Black Recording Format: WAV Music Format: MP3 / WMA / WAV Sampling Rate: 48KHZ Recording Bit Rate: 192 Kbps Recording Method: Start Recording/Shutdown Save Battery Type: Built-In 200mAh Lithium Battery How e: 1. Recording: Without plug in headphones, push the switch to the ON position to enter the recording state. 2. Pause: Long press the "+" key or "-" key to pause, short press the "+" key to continue recording. 3. Save: Push the power button to the OFF position to save the recording file and shut down. 4. Music playback: plug in the earphones, push the switch key to the ON position, enter the music playback state, short press the "-" key to switch between music playback and recording playback, short press the "+" key to play the another  song. 5. Volume adjustment: In the playing state, long press the "+" key to enter the volume adjustment interface. In the volume adjustment interface, short press the "+" button to increase the volume, and long press the "+" button to decrease the volume. Short press the "-" key to exit the volume adjustment interface. 6. Delete files: In the playback state, press the "+" and "-" keys at the same time to enter the pause state, long press the "-" key to delete the currently playing file, and press the "+" and "-" keys to delete at the same time all files.