A twin-plus-trailer set: two full-size side fins and a small third fin at the rear. It is a deliberate middle setting between a loose twin and a locked-in thruster.
A pure twin is fast and slidey and can feel like it has no back end; adding a small trailer fin restores just enough hold to stop the tail washing out, without killing the speed that made the twin appealing. Riders who find thrusters stiff and twins nervous usually end up here.
Lib Tech is a Mervin Manufacturing brand, building boards and skis in Sequim, Washington since 1977.
