Extension Cords - Harbor Freight Tools

Would these extension cords not be useful for my 30A trailer? It

Project Source 50-ft 16 / 3-Prong Outdoor Sjtw Light Duty General

100 X 14/3 Gauge Indoor/Outdoor Extension Cord, Orange, 46% OFF

100 X 14/3 Gauge Indoor/Outdoor Extension Cord, Orange, 46% OFF

9V AC/DC Adapter for Harbor Freight Tools Bunker Hill Security

Project Source 50-ft 16 / 3-Prong Outdoor Sjtw Light Duty General

AC Adapter + Power Cord For Harbor Freight Tools 60666 CenTech

4 Outlet Power Strip

12 Gauge Extension Cords - Harbor Freight Tools

100 X 14/3 Gauge Indoor/Outdoor Extension Cord, Orange, 46% OFF