THOR GUARD L75 THOR GUARD leads the world in the manufacture of lightning prediction and lightning warning systems. Since 1972, THOR GUARD has utilized our proprietary atmospheric electrostatic analysis to produce a variety of lightning prediction systems to meet the technical and budgetary demands of various customer groups. THOR GUARD’s Model L75 is our first upgradeable base prediction and warning system control center. Customers can now have an entry-level system, automatic or manual, capable of providing audible and visual warning for a single site. The L75 is fully upgradeable, so that at any time in the future, you can provide warning for remote locations up to11/4 miles away.