Review on Enhance Automotive Connections with Absolute USA SPL1614B Scotch Lock Quick Slide Auto-TAP Connectors by Tyler Owens

It's just a metal 'plug' that prestresses the insulation of the two wires that go in and a plastic body which I don't see have to buy more expensive. I haven't tested the connection with a continuity tester yet, but the connection looks solid. You can fill the cavity with silicone grease, which will probably weatherproof it, like those button wire connectors. Squeezing with needle nose pliers requires some force. It is designed to be squeezed with regular or slip-joint pliers, which offer more mechanical advantages. The cap is only meant to be pushed down and prevent the metal connector from shorting to other metals. It's not for squeezing a metal fork.