Phase Five 4.3" Thruster Fin Set - Power, Grip & Control Dial In Your Ride with Surf-Style Precision Made for surf-style riders chasing power turns and clean carves behind the boat. Tri-fin setup delivers a perfect balance of drive, grip, and fluid release on every wave. FCS compatible and ready to ride, complete with fin bag and key for easy installation. The Phase Five 4.3" Thruster Fin Set is all about performance you can feel. Designed to give your board maximum control and flow, these carbon-reinforced fins offer smooth transitions and tight responsiveness in any wake. Stock on the Phase Five Zeevo surf-style boards, this three-fin set keeps your ride locked in and ready for anything the wave throws your way.