These batteries are 1100 mah, and are adjustable from 3.2-4.8 volts and everywhere in between by turning the dial at the bottom.
These are easy to use, and they allow you to adjust your experience to meet your particular tastes. This battery is powerful enough to push a 2.8 ohm head, but also can be adjusted down for low resistance heads.
All of these batteries have the rubberized finish that feels nice in your hand. At 1100 mah, these will last all day.
They use a standard ego charger, which is not included. Here is a link to the charger for this battery: