4 Things to Know About Extension Cord Ratings

The W stands for weather-resistant If the cord has a W in its rating, it is safe for outdoor use. Without it, the cord is indoor only.

SJTW is a common outdoor cord S means Service (600V), J means Junior (300V), T means Thermoplastic insulation. The W means the jacket can handle sunlight, moisture, and temperature swings.

A cord without W will crack outdoors Without the W rating, the insulation can crack and expose wires when left in rain or sun.

Use W cords for outdoor tasks Buy a W-rated cord for string lights, power tools, or holiday decorations. A plain SJT cord is fine in the garage but should not be left in the rain.