The SeshGear Scope Vaporizer Battery is a sleek and discreet 3″ unit for use with your thick oil cartridges. A slide button allows users to retract 0.5ml cartridges into the profile of the battery for safe keeping while on the go. The bottom has a built-in USB cable so it can always be charged whenever their is access to a USB outlet. The long lasting 500mAh battery keeps this unit going all day long. The universal fitting accepts most 510 threaded cartridges. Use the included magnetic ring to thread on to your cartridge for easy drop in and take out.