The Smoov Rev is an excellent choice for those that are looking into utilizing variable voltage batteries. It comes in a variety of fun colors and each with a free Rev USB charger. The voltage adjusts from 3.3-4.8 at the bottom with marker points, so as to not become confused of the settings. The Smoov Rev has an easy five quick clicks on and off feature as well. Whether you are a beginner vaper embarking on your journey to be analog free or an advanced vaper who is always looking for a reliable variable voltage battery, The Smoov Rev is perfect for you!