Whether you are in a ship, vehicle, home or science project, heat shrink butt connectors will provide a solid water seal to ensure everything is connected properly. Features: The thick copper tube ensures a firm and secure crimp every time, providing minimal voltage drop, high current flow and less heat. These will avoid the well-known short circuits and problematic wiring of inferior connectors. Each terminal has a thick tinned copper tube, which can withstand corrosion and keep wires tight when crimped. The pen body is made of seamless copper, eliminating the problem of opening the pen body. Your wires will never slip out of the connector. The insulated hose has a unique double-wall design. The high-quality 3:1 shrink tube has a heat-activated seal liner to provide a secure 360-degree seal. Flame retardant, waterproof, can be used underground. Wire gauge printing on connectors and color identification. Translucent provides tensile strength, allows for visual inspection. It meets all