These Wallis high-strength couplings are used for joining copperbond threaded earth rods together. They facilitate deep driving and ensure continual contact between the rods both during and after installation. The coupling also protects the earth rod threads during installation with the driving head. There is a lead-in for ease of assembly and a hex on the outside for grip and keeping the coupling tight when driving into the ground. All Wallis couplings are manufactured from a high copper content alloy ensuring excellent corrosion resistance.