Swap in a new replacement coil for Smok TFV12 PRINCE Coil when flavour drops off or you notice a burnt taste. Sold as a single unit unless otherwise noted on the product listing. Choose your preferred resistance/style (tighter MTL vs warmer, more open draws) where options are available. Replace when vapour output drops, flavour tastes off, or you notice leaking/gurgling. Install, fill, and let it sit a few minutes before vaping. Replace as needed. 19+ only.