For solid concentrates, most coils will either use a ceramic rod, a quartz rod or the same materials in the shape of a donut (AKA Donut Coil). Diluted oil and eliquid vaporizers will often use cotton wicks in their tanks. For dry herbs, two very popular style of heating chambers will provide a full vaporization effect. The most popular is the “convection style” conduction vaporizer. The reason we say this is because air is heating the herbs, usually at a specified temperature on the vape. Although, at this time there is still a hot plate touching the herb, so some may still consider this to be a conduction heating method even though the herbs are vaporized and not burned if the temperature is set accordingly to the moisture level of dry herb used. The rare but pure vaporizing chamber is the full convection chamber. This will lift the herbs on a screen, away from any hot surface to vaporize all pieces of the dry herbal blend equally.