Ilsco became the standard for grounding lay-in lugs in solar photovoltaic applications. The Ilsco GBL-4DBT is a tin plated copper lug compliant with NEC requieremnts. The Ilsco GBL-4DBT is rated for direct burrial, suitable for all ground mounted solar installations.
It comes with a stainless steel hex screw, and a 10-32 thread forming screw & lock-tooth washer (not shown in picture).
Ilsco part No. GBL-4DBT