A one-part or two-part air terminal for protecting a structure against lightning strikes. A flexible adapter, such as a spring, attaches an upper air terminal to a lower air terminal or a one-piece air terminal and base. The flexible adapter allows a flexible engagement between parts of the air terminal and has an internal passageway. A elongate tether couples parts of the air terminal in case the upper air terminal or one-piece air terminal breaks, so as to avoid a broken part from injuring individuals around. The elongate tether may be a ball chain or other type of chain. The elongate tether runs through the internal passageway of the flexible adapter. A base mounts to the one-part or two-part air terminal and mounts the air terminal to the structure. A grounding wire grounds the base to the grounding rod.