LOKBOX is an adjustable fin system, which means that you can adjust your fins forward and back from your shapers mark (neutral position) to change the way your surfboard rides similar to the way that tires can optimize the performance of a race car. By utilizing the adjustable features of the LOKBOX fin system you can fine tune your surfboard. Whether its getting the most out of your surfboard or fine tuning it for different conditions, LOKBOX offers you the ultimate fin system.