Eleaf Aster RT 100W Battery Box mod, is a skillfully designed "Recessed Tank" (RT) style compact mod that is able to hold and hide tanks up to 22mm diameter. It is pre-installed with the new firmware that has preheat function and custom logo as well as different interfaces for you to check your total puffs and total vaping seconds. Also the firmware is upgradeable to be always the latest. Please note this mode is ONLY compatible with tanks which diameter no bigger than 22mm. Detachable Structure for Easy Cleaning Recessed Tank Style Compact Mod Built-in 4400mAh lithium-ion battery Innovative Retractable Top Filling Solution Preheat Function Available Compact yet Powerful and Sustainable Different Switchable Interfaces for Your Option Fits 22mm tanks or less then 22mm tanks Brand: iSmoka Eleaf Model Aster RT Output Wattage 1-100W Resistance 0.3ohm Size 96 x 51 x 40mm