Future Surfboard Fins Twinzer Fins Twinzer/Quad Height: 5.125 in-13 cm Base: 4.813 in-12.2 cm Area: 19.8 in-127.74 cm Fin set includes 3.25 in-8.3 cm leader fins. Twin fin feel with added thrust and smoothness rail to rail. A fun ride for summer! Available Materials: Fiber Glass (clear & smoke)