Where properly grounded electrical equipment is top priority, you need this 50 ft. 10/3 SJTW Heavy-Duty Lighted Extension Cord. It offers Continuous Ground Monitoring (CGM), a safety feature needed at all high profile and hazardous jobsites. The connector features a green ground check light that lets you know the cord“s electrical current is safely grounded, and an amber power check light on the plug that indicates power delivery through the cord. This cord“s jacket is rated at -40°F, providing working flexibility in temperatures below freezing.