10/4 SOOW is ETL approved. SOOW stands for S = Service Cord, OO = Oil Resistant (both inside and outside insulation), W = Weather and Water Resistant. 10/4 SOOW APPLICATIONS: portable power, electric vehicle chargers, extension cords, heavy equipment, construction machinery, motor leads, welding leads, portable lighting, battery chargers, shallow water immersion, mining environments, and applications where a rugged, heavy duty flexible multi-conductor cable is required.