( 3 Fin Set ) Futures Compatible Twins + Trailer: One of our newest offerings, the High Pro Twin + Trailer was designed and developed in-house here at True Ames after some extensive R&D. Constructed from high quality solid fiberglass, these fins are firm, stable, and excel at producing lift in a wide variety of conditions. These fins will provide down-the-line speed, power off the bottom and through the lip, as well as smooth rail-to-rail surfing. Surf this set as a twin for a slightly looser feel in your performance oriented boards, or add the trailer for a bit more stability that will mimic more of a thruster type feel. If you like the feeling and freedom of a twin, but the performance and maneuverability of a tri then these fins might be a good option for you to try out. (Front – Twin)HEIGHT: 5.10″ / 130 mm BASE: 4.96″ / 126 mmAREA: 19.28 / 124.39 cm(Rear – Trailer)HEIGHT: 3.30″ / 84 mm BASE: 3.28″ / 83 mmAREA: 8.35″ / 53.87 cm -Front fins – 3/4″ Futures base, 6.5* angle, flat inside foil -Rear fin – 1/2″ Futures base, no angle, 50/50 foil – to be used as a center trailer -Solid fiberglass construction, raw sanded finish