NEW! Our most compact and advanced battery yet. The brand new Mini Battery fits everything you love about Boost batteries into an even more compact device. Sturdy + precise hardware features a new digital screen for ease of use, more advanced user customization (1.8v-4.2v), and faster 15sec preheating function. Device is compatible with 510-threaded cartridges and USB-C universal charging cables. Shipping and Return Policy BOOST! Battery Instructions Specifications Size: 53.4*21.5*19.4mm Capacity: 420mAh Type C Charging Port Voltage Adjustable: 1.8V-4.2V 15s Preheating Function