An extremely important type of electrical protection systems is lightning protection for buildings. Nowadays, electrical equipment and installations are ubiquitous, and the potential impact of powerful lightning energy on them will destroy them completely, exposing us to huge costs associated with their replacement. One of the important accessories that are part of the lightning protection system for buildings is the clamp screwed to the ground rod 42.2 OC. The clamp itself is an inconspicuous object, however, it is an essential element used to build a complete earthing system (i.e. an earthing installation). The diameter of the ground connection is 16 mm (standard size in ground installations). The diameter of the clamp plate is 57 mm, it is screwed with a screw with a diameter of 16 mm. Its total weight is 0.25 kg. It is an item made of quality steel, which is characterized by high resistance to mechanical damage. Thanks to the additional use of galvanic galvanizing, it has gained insensitivity to corrosion, making it a durable and durable product. The manufacturer of the clamp, Elko-bis, is a manufacturer of high-class lightning protection systems.