lightning protection or earthing system LMM By far the largest and most important component of any structural lightning protection or earthing system is the actual conductor. Selection of the correct conductor type for the installation is highly important, and is likely to be the initialconsideration of a lightning protection or earthing system designer. A comprehensive range of LMM copper and aluminium conductors are available in each of the main world standardformats, i.e. flat tape, solid circular and stranded. Additionally each format is available in a variety of conductor sizes ,to meet differing lightning protection and earthing requirements. Specification will depend on whether the application is for an above ground structural lightning protection system, or a below ground earthing installation.