Glass Flex is a composite material (40% glass) which is designed to mimic the feel of a traditional fibreglass fin, it's not as light as performance core but has a natural response when surfing.
FCS II Accelerator GF Medium Fins Tri Set $89.00
FCS II Reactor GF Medium Fins Tri Set $89.00
FCS II Performer Glass Flex Fins Tri Set $89.00