Hopkins 12 Gauge Endurance™ Replacement Ground Kit. Ground problems are the leading cause of trailer electrical and lighting failures. Endurance Ground is the fix for common lighting problems including lights flickering, lights not working, wrong lights blinking and rusty grounds. Trailers are continuously exposed to the harsh conditions. Protect your trailer ground with endurance for years of hassle-free use. Ultimate waterproofing- rubber seal protects ground surface. 12 gauge wire. Stainless steel washer provides long life ground. Marine grade splice protects wire from corrosion.