All parts of the modular sonar foil system are assembled with Torx T40 screws. We recommend applying a small amount of the marine grade grease provided in the tool kit to the threads and underside of the heads of the screws before assembling your foil (make sure all surfaces are free of dirt or sand before assembly). This Torx T40 screwdriver and marine grease tool kit is included with the complete foil editions. We do not recommend the use of power tools for foil assembly as they may cause damage (as torque and power control is limited) and will void your warranty.