With mp3 function: very suitable for conferences, speeches, investigations, and evidence collection. It can be used for 28 hours after fully charged. Charging time: 0.5 hours, please charge before use.Ultra-small size (35*30*5mm): easy to put in any pocket or purse. The time stamp can be added as a reference point for any recording, just connect the device to the USB 2.0 port of the computer, and then click the time tool in the file in the removable disk to set the time stamp.One-button, simple operation. Turn the switch to "ON", the red indicator light will light up and stay on for 15 seconds and then go out---means that it is recording. Turn the switch to "OFF" to save the recording.Voice activated recording (VOR mode): When a sound is detected, it will automatically start recording, you can avoid long silent recording.It takes 20-30 minutes to fully charge. You can charge it via a USB wall charger or a computer USB 2.0 port. Please do not charge for a long time, otherwise it may damage the battery and casing.