Start with your exact device. Almost every Aspire coil and pod here is built for one kit and will not fit another, so the first job is matching the part to the kit you own, whether that is a Flexus, a Cyber S, a Gotek or a Nautilus tank. Each product page lists the devices it works with, and our staff will check it for you if you are unsure.
Then pick the resistance. The ohm figure sets the style of vape: a higher number like 1.6ohm or 1.8ohm gives a tight, cool MTL draw at low power, ideal with nic salts, while a lower number like 0.4ohm or 0.6ohm gives a looser, warmer draw with more vapour. The Nautilus BVC range spans 0.7ohm to 1.8ohm so you can choose the draw you like.
Finally, check whether your kit uses a pod with a built-in coil or a separate replaceable coil. Cyber, Gotek and Flexus Pro users buy a whole pod, while Nautilus tank users buy just the coil, and the Flexus uses a separate AF coil inside its pod. Packs hold two or five units, so a single purchase keeps you going for weeks.