The 3.5ml Geekvape Z (Zeus) nano 2 tank is an upgrade over the Geekvape Z nano tank. It features an adjustable top airflow system, a top filling design, and a Geekvape B series coil that is designed to give you the flavor you deserve. https://www.vapeuniverse.co/products/geekvape-z-zeus-nano-2-tank?pr_prod_strat=pinned&pr_rec_id=e35f2331b&pr_rec_pid=7846693470460&pr_ref_pid=7846693863676&pr_seq=uniform