[INCREASE SURFING STABILITY]-- The center fin can increase the stability of the surfboard to keep you safe when surfing. And 2pcs small watershed fin are generally glued to the two sides of the board surface, which assists the use of the central large water-dividing sheet to increase the stability and directionality of the surfboard. [DURABLE & DETACHABLE & SIZE]-- Made of superior PVC material, wear-resistant and durable. Our central fin has a retaining clip that can be fixed to or removed from the fin base. Please make sure the specification needed before you purchase. [EASY TO INSTALL]-- This surfing watershed fin set is easy to install. Just use glue on the bottom of base or on the surboard to fix the fin base on the surfboard, then insert the fins into the base. Please note that the glue does not included, you need to buy the glue before installing. It is recommend that leave them to rest for 24 hours after applying the glue. [FERFECT FOR VARIOUS SURFBOARD]-- Used for surfing board water sports, suitable for some inflatable surfboards including shortboard, longboard, stand up paddle etc. It can be also installed to kayak to divide water and decrease the water resistance. Colour:Black Material:PVC Package Contents: 1 x center fin 2 x small fin 1 x base Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.