If you have similar confusion, please read this thread.
What is the difference between Qtc and Qdc and what is each one used for?
Quartz Triple Coils (QTC) is outfitted with 3 quartz rods wrapped in coils. It made for giant clouds and big hits.
Quartz Dual Coils (QDC) is a set of dual quartz rods wrapped in stainless steel, outputting delicious flavor from your concentrates. The QDC replacement coils are a convenient and fast way to enjoy your favorite CBD wax concentrates.
If you want more cloud, the QTC is your option. Or you can consider the QDC coil.