The Prime Wire and Cable 100-Feet 10/3 SJTOW Yellow Bulldog Tough Ulta Heavy Duty Extension Cord with the Prime light Neon Lamp embedded in the female connector to let you know when the power is on. The circuit is designed so that if the lamp fails, it will not affect the operation of the extension cord. This is perfect for heavy duty applications for contractors and home users. They are Water and Oil Resistant, Flame Retardant, Ultra Flexible, Abrasion Resistant and Nickel-Coated Brass Blades Resist Corrosion. Flexible Temperature Range (-58F - +221F).