* backward compatible * to use old fcs fins in new fcs II system * Comes with Key * Infills for all plugs * re usable bag FCS II Tab Infill Kit are a must have if you want to use your old style FCS fins in your new FCS II plugs. This kit allows for backward compatibility. Without the tabs in place you will have holes causing drag and an unstable fin setting so don't mess around, attach your fins properly with the infill tab set. The FCSII Compatibility Kit includes: • Centre Compatibly Infill (x1) • Side Compatibility Infills (x4) • Grub Screws (x10) • FCS Key (x1) • Reusable zip lock bag