The rear Stabilizer’s main role is to maintain a level and stable flight path. But conditions and user preference may change what stabilizer angle feels the best (aka the sweet spot). Shimming changes the angle of attack (AOA) and controls the amount of downforce the stabilizer creates on the overall foil system - to increase the stabilizer AOA and front foot pressure, add positive shim. The smallest tweak in the AOA can improve comfort, reduce fatigue, change the cadence of your pump or the turning radius of your carve and increase/decrease your front and rear foot pressure without changing your foot position. With the Sonar Shim Kit you can stack multiple shims, from our base setting it covers from -0.5 to +2.5 degrees. Finetune the way your foil system performs and change the way you ride. You’re in control.