The Aspire Nautilus X Replacement Coil is specifically designed for the Nautilus X Atomizer Tank. The mouth-to-lung (MTL) 1.5 ohm atomizer heads have an output range of 14 - 22W. Utilizing the U-Tech coil structure, allowing the vapor to pass through the U-shaped chamber and hitting directly to the coil. The original Nautilus tank was Aspire greatest ecigarette atomizer tanks. The Nautilus X replacement coils provide exceptional mouth-to-lung vaping with robust flavor and vapor.