Preheat Functionality: Some batteries feature a preheat functionality, helpful for getting ready thicker concentrates in advance of vaping.GuidesGuides 2Guides 3Guides 4Guides 5Guides 6Guides 7Guides 8Guides 9Guides 10Guides 11Guides 12Guides 13Guides 14Guides 15Guides 16Guides 17Guides 18Guides 19Guides 20Guides 21Guides 22Guides 23Guides 24Guides