The TWISTER® AL/Cu wire connector is the only UL listed aluminum to copper twist-on connector that prevents aluminum oxidation while providing a secure connection. Filled with an anti-oxidant compound, the TWISTER® AL/CU easily twists on with swept wings making a comfortable connection with improved conductivity and cooler connections. The live action spring expands and contracts with aluminum wire to ensure a secure connection while the hexagonal head makes for quick and easy installation by hand or with a standard nutdriver.