If you purchased your first RDA or RTA, building the coil might seem a little daunting. Pre-built coils are the simplest solution. Pre-built coils are short pieces of coil wire that have already been wound up like a spiral. When choosing a pre built coil, you should simply look at the available resistance values and coil metal.
Is there anything else I need to know?
Keep in mind that most pre-built coils have the leads pointing in the same direction. In case your build deck requires that the leads point in opposite direction, you need to either unwind or wind the coil further. If you wind it further, the resistance will rise slightly. If you unwind, it it will decrease. Make sure you insert a coil jig or screwdriver in the core of the coil, so it does not lose its shape.