The GX 2/4 kit is a new product from SMOK that offers users the option of dual-18650 and quad-18650 performance. The GX 2/4 mod is paired with the TFV8 Big Baby tank, which has a capacity of 5 mL (2 mL in the EU). The mod powers up to 220 watts with two 18650 batteries. By replacing the battery cover, the user can add two extra 18650s to the kit, increasing battery life and maximum wattage up to 350 watts.