Designed specifically for surfers in mind. Thruster I is the original spring loaded turning mechanism. Designed to fit directly onto the skateboards front trucks. Allows the front trucks to turn freely way beyond a normal front truck skateboard set up. This allows the board to become self propelling, no pushing is required. When fitted to your board, it becomes one of the best surf training tools available. Constructed of strong aluminium, steel springs washers and bearings. The Thruster I is adjustable for extra control on slopes to loose feel for the flats. It also fits all SmoothStar models and most other skateboard brands offering similar results depending on the length of your board and height. Please note: the SmoothStar Thruster I is not recommended for decks under 25″