I own: quad stretch controler S3, 2x fcs S2 five fin set, 1x future set and fcs S2 step up/gun quad set plus 2x 2win set. Love them all and only take them out of a board for travelFiberglass Stretch sets. hear these are not easy to find:
https://sfbay.craigslist.org/scz/spo/d/aptos-stretch-surfboard-unlimited-fins/75946572,92.html