Copper bonded earth rods exist in a range of diameters and lengths to fit various grounding needs. The most popular diameters include 12.5 mm, 14.2 mm, 17.2 mm, 19 mm, and 21 mm, though 17.2 mm is usually regarded as the standard size for most installations. As regards the length, these rods are usually available in lengths like 1200 mm, 1500 mm, 1800 mm, 2000 mm, 2400 mm, and as high... https://www.pioneerpowers.com/copper-bonded-earth-rod.php