The Reewape RUOK Ghost 21700 Mechanical Mech Mod is a full high-end pure copper mech mod of RUOK, which is constructed from copper material with PVD coating and powered by 1 x 18650 / 20700 / 21700 battery (Not included). The Mech Mod uses unique Innovative Three-Piece clutch connected button. Importantly, it is compatible with 22mm, 24mm, 25mm, 26mm RDA... Learn More