IJOY BIG MOUTH: ergonomic spin dial for adjusting the voltage, adjust range from 3.2V to 5V. powerful 1670 mah with 2ml big mouth BDC/Stainless atomizer. (email:sales19@ijoycig.com, skype:ijoysales19) different light color indicates different power remaining: Blue light color for 90% available, and green for 60%, red for 30%. Longer life span with one year warranty.