The kanger ceramic 0.5ohm replacement coil is a new and exciting prospect,it is much more durable than other coils. compared to a normal coil core, it has a few advantages. there is no burning smell even when you vape it dry without e- juice for seconds! and it's healthier because cotton does not touch coil, except for the outside of ceramic core. what's more, it has long life-time which can be up to 2 or 3 months or longer(35w-60w) if not abused with high wattage. 4.from inside to outside is coil-ceramic-cotton and make sure to prime coil prior to firing