These tin-plated copper lugs have stainless steel set screws and come with either stainless steel thread forming screws and lock washers, or a longer thread cutting stainless steel screw with stainless steel star-washer kep-nut. Pick the type that meets the module manufacturers requirements. They meet NEC requirements for connecting a continuous ground wire to all modules. Sold in packages of 10 with SS screws. UL Listed.