FinSciences FCS-tabbed shortboard fins (FCS1) will fit into other boxes with the use of fin-box adapters available here.  Often surfers have Futures bases, and ask whether our FCS-tabbed fins will fit their Futures-based boards.  They willwith an adapter.  Likewise, a fin-box adapter can make our FCS-tabbed fins fit into longboard boxes, should you wish to try downsising to that extent.