510 Thread Wax Atomizer
The thread aka threading, is the part of the coil that screws onto the vape battery. If you have a battery with 510 threading, you need a 510 thread coil, but there are many types of 510 coils that may or may not work with your exact vape. Two vape pens can have 510 threading but one may be slimmer than the other.
Multi Coil Atomizers
A single coil will get the vaping job done. But many users want large puffs, bigger dab hits, and a more powerful vape battery does not necessarily cut it. More coils equals bigger hits, but that also results in a hotter vapor which can be harsh, especially to those sensitive to smoke or vapors.