Liquid Force Primo Wakesurf Board One of the most unique features about the Primo is its fin configuration. You can ride your Primo as a Twin or a Skim. As a twin fin that has a surf-style vibe or completely flip the script by running a single rear fin to compliment a more skim-style session. Features Dura-Surf Construction Stringerless EPS Foam Core Single Concave with Quad Channels Squash Tail EVA Surf Traction Pad Tri Fin Setup 2 Dual Tabbed Surf Style Side Fins 1 Dual Tabbed SK Center Fin Sp