Professional Answer: A subtransmission line is an intermediate stage between the main transmission system and the distribution system. It typically operates at a voltage lower than the main transmission lines but higher than the local distribution lines (e.g., 34.5 kV to 69 kV). Subtransmission lines feed regional distribution substations, and sometimes large industrial customers, bridging the gap between the bulk power grid and the local power network. We provide a full spectrum of equipment and tools to handle projects at all three levels: transmission, subtransmission, and distribution.