The AT-CV1KSS has two 1000X SFP ports that can support both copper and fiber optic SFPs. Either of these ports can be populated with: - Multi-mode fibre SFP module, capable of driving a maximum operating distance of 2km (1.24 miles). - Single-mode, dual fibre SFP module, capable of driving a maximum operating distance of 80km (49.7 miles). - Single-mode, single fibre SFP module, capable of driving a maximum operating distance of 10km (6.2 miles). - Copper SFP module, capable of driving a maximum operating distance of 100 meters (328 feet) at 1Gbps speeds only.