The STR8 Slim Revolve 320Mah 510 Vape Battery with included vape battery charger gives you full control over a variable voltage vaping experience. With a range of 2.0 to 4.0 volts of power at your disposal, you can custom craft your vape experience to your personal standards of perfection. Variable voltage wax pens also give you a wide vista of compatibility options for vape cartridges so you can really hone your experience. This is the perfect vape battery for those of us who like to experiment with oils of widely differing viscosities. You can activate this vape pen battery through a simple twisting motion with the illuminated fire button keeping you fully aware of the power situation. A preheat mode is built in to get you started.