I have a 28mm magma which I vape on everyday. The airflow is a little restrictive, but there is plenty for good clouds, while still not sacrificing flavor. Still not sure if I like single or dual better. Warmer vape lovers will appreciate the magma in dual as she gives a smooth satisfying warm vape, and in single coil mode the flavor is outstanding. Still tinkering on it, will update if I find that perfect vape that I am always looking for.