The Gemini Mega RTA by Vaporesso is a Dual Post Rebuildable Tank System that Implements a Wider Diameter and a Large E-Liquid Capacity. Key Features of the Gemini Mega RTA include a durable construction, high airflow, and a top fill system to keep the mess out! The Gemini Mega RTA is constructed of a Durable Stainless Steel Construction with Pyrex Glass and a Delrin Drip Tip to Prevent Hot Hits and provide a Clean, Smooth Puff. Featuring Quad Adjustable Bottom & Top Airflow ensures your Tank will not be "Choked" and will allow the coil to breath and perform at its peak. The Top Fill System allows you to re-fill your Gemini Mega without the need to disassemble your entire tank ensuring a Quick and Easy Fill. For a Quality RTA that will ensure Performance and Durability, The Vaporesso Gemini Mega RTA is the way to go!