Reposition your mast without leaving the water. These lightweight titanium screws are designed for fast foil mounting and adjustment no tools required. Simply loosen the screws by hand to slide your mast forward or back in the DropBox track, then re-tighten byhand. The 30mm Thumb Screws are compatible with Seek, Swell, Scoop, Horizon and Vert Foilboards or any other board using M8x30mm screws. They are not suitable for use with the Sense, Seek Air (M8x23mm) or Scoop Mini (M8x25mm) WARNING: Tighten by hand only. Do not use any tools, and do not over-tighten. Screws may not align with your mast. Due to the reduced torque moment of the thumbscrews, the screws can loosen more easily. Always check screws are tight before and during each session.