✔️【PREMIUM QUALITY】Thick copper barrel ensures strong secure crimping every time, providing minimal voltage drop, high current flow, and less heat. These will prevent short circuits and problematic wiring that inferior connectors are known ✔️【DURABILITY】Each terminal features a thick tinned copper barrel that resists corrosion to hold the wire tight when crimped. The barrel is created from one seamless piece of copper that eliminates the problem of the barrel opening. Your wire will never slip out of the connector ✔️【WATERPROOF】Insulation tubing has unique dual-walled design. High quality 3:1 shrinkage tubing has a heat-activated sealant lining to provide a 360 degree secure seal. It's flame-retardant, waterproof, and can be used underground ✔️【WIDE APPLICATIONS】Compliant with all electrical standards, Perfect for marine and automobile applications, whether you are working on your boat, Vehicle, Home or scientific project, our electrical crimp connector will ensure strong watertight seal to make sure everything bond correctly.