Review on 🔌 BougeRV Connectors Branch Parallel Adapter: Simplify Your Power Needs with Ease by Todd Markel

4 mm² = 12AWG. The wire is pretty tough. The connectors do not appear to be waterproof and do not come loose on their own. I'll probably cut off one end and splice some of my own wire instead of buying an expensive extension cord. Double wall heat shrink should work well enough to keep water out of the joints.