The DUO Variable Voltage Plus Dual Cartridge 510 Vape Battery from HoneyStick can hold one or two cartridges to double the vaping power and is ultra easy to use with auto-draw activation! Whether you prefer rich flavors or huge clouds, users can select their perfect preference with 4 preset voltage settings to choose from. The vape battery has universal 510 threading and works with most vape cartridges (up to 2mL). The device has a powerful 600mAh battery with an 8-second preheat mode for thawing cyrstalized cartridges. Charge up quickly with the included USB-C charge cable!