The ARO battery is very similar to the eGo. It still has the same 510 and eGo threading, but the button has been redesigned to be more durable and reliable. Since the button is flush against the rest of the body, there is a lesser chance of it getting caught on things or getting stuck. The chrome "collar" has been removed, which allows many of the newer tanks, like the ARO, to look more uniform and put-together than if you had put it on an eGo. This is a variable voltage battery, capable of putting out voltages between 3.2 and 4.8 volts, and can use a myriad of tanks and atomizers. If you can use it on an eGo battery, then you can also use it on the ARO. This is a huge 1500mAh battery that should last the average user about 15 hours of constant use!
Note: For a complete charge, be sure to set the battery to 4.2 volts before charging.