Review on 🔌 2Pack of Heavy Duty SPARKING 3FT 10AWG SAE to SAE Extension Cables with Waterproof Cap - Quick Connect Wire Harness for Bullet Connections by Larry Blanco

I cut mine and the wire inside is not copper colored. Not sure what it's made of. Looks and feels more like aluminum but I don't have any test equipment to verify this. The insulation is nice and thick and the wire inside actually seems thicker than other 10AWG wires I have (copper inside). So it's probably electrically equivalent to 10 AWG copper in conductivity, but the extra wire gauge and insulation prevent me from using these wires with the connector I intended to use on one end. 4 of them just don't fit through the hole in the connector. I couldn't find any "loose self-aligning" SAE end connectors to add to my existing cable, so I bought a pair of these to snip off one end. them and add another connector to them. It didn't work and exposed those innards.