Couplings made of brass which is then nickel plated in order to improve resistance to hard environmental conditions in which they are used. These connectors allow the coupling of two identical male threads and therefore cannot be used with non-threadable metal conduits. The connector is coupled to the rigid conduit by screwing it onto the conduit. If screwed together correctly the level of protection is IP67, and electrical continuity is in line with CEI standards. UNI ISO 228 GAS cylindrical.