Get SOOW if you need tough. SJTW is fine for light duty.

It’s simpler than it looks. Those letters are just a code for insulation type and intended use.

SJTW stands for Service Junior Thermoplastic Weather-resistant. That’s your standard orange or yellow extension cord you see at any hardware store. The “T” means thermoplastic insulation (cheaper, less flexible in cold), and “W” means weather-resistant (okay for outdoor, but not meant to live outside). It’s fine for power tools, yard equipment, or Christmas lights—temporary use.

SOOW is Service Oil-resistant Over Weather-resistant. The “O” stands for oil-resistant rubber jacket—much tougher, more flexible in freezing temps, and stands up to oil, chemicals, and abuse. It’s what you see on construction sites, in garages, or anywhere the cord gets dragged around, stepped on, or lives outside for weeks.

How to interpret: Look at the wire gauge (AWG) first—lower number = thicker wire = more power. Then check the letters. For occasional indoor/outdoor use, SJTW is fine. For constant abuse or outdoor permanence, spend the extra on SOOW.

Future You will thank you when the cord doesn’t crack in January.