Normal working voltage: 3.3-4.2V
Charging time: 4-5 hours
5 click on/off function
Life of the battery: more than 300 times charging
Colors: Black, Blue, Pink and Stainless
Decided to try this because it was $10 cheaper than the Kanger EVOD 1600's I've been using. I was skeptical because the GreenSound is about 1" shorter than the Kanger. After charging, the GreenSound lasted around 2.5 days verses the Kanger at around 1 day. The power is consistent and I don't have to worry about constantly checking the variable voltage knob. It's comfortable to hold and the button is in the right place. I also like that it gives you some idea of how much charge you have left. I will definitely be buying more for both myself and my girl friend.