The Aspire Nautilus BVC Replacement Coils - 5 Pack are a pack of five BVC - Bottom Vertical Coil units for the Aspire Nautilus and Aspire Nautilus Mini tanks. Each coil in the pack comes with an improved design, organic cotton and enlarged wicking holes ensuring a better absorption, richer vape, finer flavour and superior production of vapour clouds. These BVC Replacement Coils are available in resistances of 1.6 ohm and 1.8 ohm. NOTE: These BVC Replacement Coils are compatible only with the Aspire Nautilus, Nautilus Mini and Triton Mini Tank models. To achieve the best vapour clouds and taste of your favourite e liquid we suggest that the coil should be replaced every 1 to 3 weeks, depending on the frequency of usage.