A bulk 18/3 SJT extension cord wire is a flexible electrical cable with three 18 AWG copper conductors (hot, neutral, and ground) inside a durable black thermoplastic jacket. It is commonly used for making extension cords, power leads, and light-duty equipment wiring.

SJT stands for Service Junior Thermoplastic, meaning it is designed for portable use with moderate flexibility and durability, typically rated around 300 volts and 10 amps.

• 18/3 gauge (3 conductors: black, white, green)
• Flexible PVC jacket for easy handling
• Rated approx. 300V / 10A for light-duty power use