This quad fin set is what comes with all surf style Phase 5 wakesurf boards 53 and smaller. The 3.7 surf fins provide great feel with less hold than the larger 4.3 size. The fins are an e-glass honeycomb construction for optimal performance. This quad fin set includes a total of four fins: two 3.7 surf fins and two smaller trailer fins. The fins are compatible with any wakesurf board that has FCS fin boxes. Includes a fin bag and FCS fin key.