Please Note: Rebuildable coils like these can only be used with rebuildable atomizers, such as RDTAs, RTAs and RDAs. We would only recommend these types of coils to advanced vapers, who have a thorough understanding of vaping, Ohm’s law and battery safety. Rebuildable coils will need to have cotton wicks fitted to them before use, these are available separately. Before use, all rebuildable coils should be tested on Ohm meter (never a vape device) to check they are registering the correct resistance and are firing correctly. Please note that when using a dual coil build, the resistance of your coils will halve. For example, two 0.4 Ohm coils fitted to a rebuildable atomizer will register 0.2 Ohm. Different types of coil can not be mixed and matched.