Futures Fins TMF-1 Knubster

If you have a quad fin setup on a wakesurfboard then you will want to get these rear fins.  These are designed for all futures fins boxes which are available on most wakesurfboard setups.  

More info about the Knubster:

The original Knubster was developed by Sean Mattison for Von Sol surfboards, the Futures TMF-1 (The Middle Finger) Knubster is a 5th. Fin center fin that can be added to any quad set-up. The fin will increase drive and provide directional control through turns without sacrificing speed, flow, or the freedom of movement typically associated with a quad. The raked template with the extended length of the base provides increased stability for any board and may work best in boards with larger tail areas.

The Future Fins TMF-1, which is 3.76" by 1.76 high, is a similar template to the FCS Knubster that Kelly Slater used as a 5th. Fin on his quad during the Quiksilver Pro in New York. According to Kelly's report, "The FCS Knubster will make your quad set-up feel faster, smoother, and it adds a little more control".

The  Future Fins TMF-1 (The Middle Finger) is made from Futures' world famous Composite material giving it the perfect amount of flex at a great price point!
 
The Future Fins TMF-1 Knubster Fin Size:
Base: 3.76 in. 95.50 mm
Depth: 1.76 in. 44.7 mm
Area: 4.85 in. 123.19 mm
 
The Future Fins TMF-1 Knubster Fin: Available in White Composite