Review on 🔌 Eventronic Waterproof Electrical Automotive Connectors by Bryce Wohlman

These are made from very thin metal such as chrome plated brass, they are definitely not tin plated copper like most quality connectors. Also, they don't make a tight connection because the shrink tubing doesn't cover the stripped end of the wire. You can also use a non-hermetic connector. As usual "you get what you pay for" but I wouldn't pay for that.