HW-S6800-HI-4P2F-L2+ Industrial PoE Switch, 4x Gigabit auto-sensing RJ45 ports and 2x Gigabit SFP optical port, is designed for the security of industrial automation and coal mine factory. It is easy for setting any ports to build a fast self-healing looped ring and the time is less than 50ms, and provide a safe network environment.