horizontal FMIC is the charge area and the length of the core. The Vertical has greater charge area but shorter cores. This is much less restrictive vs less charge area and longer core. Think of it as blowing air through straws. Which will have less restriction, blowing air through 12 straws that are 6 inches in lenght vs. 6 straws that are 12 inches in length. They both have the same frontal area but one has less restriction than the other.
