The SeshGear Mobi is a pocket friendly thick oil vape battery that is extremely stealthy at 2.8" tall. A dedicated voltage shift button allows the user to quickly change the voltage level to their liking. The built-in pre-heat function primes the cartridge for use and provides a perfect flavorful hit. With a universal opening this unit can accept cartridges up to 11mm in diameter (cartridges sold separately). This device uses 510 threading, not magnetic adapters. Features - Pocket friendly design - Extremely stealthy - Pre-heat function - 4 voltage settings - Independent Voltage Shift button - Fits most cartridges on the market Specifications Size: 23.5x18.5x71mm Battery Capacity: 650mAh Wattage: 15W Voltage: 2.8V, 3.2V, 3.7V, 4.2V Preheat: 2 clicks with 2.2V for 17s Charger: USB charger Package Contents 1 - SeshGear Mobi battery 1 - USB charge cord 1 - User manual How To Use Power On/Off - Press the power button 5 times rapidly to power on/off. Preheat Function - Click power button 2 times to preheat. Changing Voltage - Click the Shift Button 1 time. 2.8v is indicated with 1 light, 3.2v is inidicated with 2 lights, 3.7v is indicated with 3 lights, 4.2v is indicated with 4 lights. Charging - 1 light means 25% charged, 2 lights means 50% charged, 3 lights means 75% charged, 4 lights means fully charged.