The 7.5" to 8.5" Christenson will work amazing in your favourite mid length board. Or step it up to the 9" to 9.5" for your everyday log.
They benefit from this year top innovation: the FCSII system to set up and take off fins without tools. Adapted to longboard boxes and 99% of US boxes.
Construction:
Performance Glass: the fins built with the performance glass technology are flex and have similar characteristics than fiberglass fins but with more response and durability.