The Gantry Free-Flow Tolling RSU is developed for high-efficiency, high-concurrency transactions in expressway free-flow scenarios. It uses power amplification to achieve stable long-distance signal coverage. The product supports online operation and section-based transaction modes, and can be used for path identification, ramp pre-transaction, traffic information collection, ETC smart refueling, and other applications, providing efficient and reliable technical support for smart expressway tolling systems.