Rugged industrial-grade port-powered opto-isolated RS232 repeater / extender, port-powered, no external power or RTS, DTR required | Extended Distance: 1.8 miles (3km) for 300bps baud, 1.5 miles (2.4km) for 1.2kbps baud, 0.75 miles (1.2km) for 9.6kbps baud, and 1600ft (500m) for 28.8kbps baud | 2500V optical isolation, operating temperature: -40ºF to 185ºF (-40ºC to 85ºC) | 300 to 28.8K Baud operation (auto-sensing & self-adjusting) | Built-in 600W surge protection, 15kV static protection and circuit protection