Use Standard Media Converter Switches in clean, temperature-controlled areas of +32 to +104° F (0 to +40° C), such as offices and closets. Hardened Media Converter Switches suit -13 to +140° F (-25 to +60° C) operation in dusty or dirty environments. Their sealed cases are a heat sink, so no internal airflow is needed for cooling, and they resist contaminants such as dust, dirt, and moisture. For harsher environments of -40 to +167° F (-40 to +75° C), choose Extreme Media Converter Switches. These rugged units are for outdoor use (they only require protection from water) and feature a sealed case, which uses its own metal shell as a heat sink.Power supplies with recessed IEC connectors work with any IEC standard power cord, making them adaptable to most international locations.DC-powered Hardened and Extreme units have internal screw termnals for connecting DC power in addition to the AC power jack.You can use them simultaneously with both your DC power supply and an AC power adapter (sold separately) to provide redundant power input.You can also order a Powered Rackmount Tray, available with one or two common AC adapters that output 9 VDC to 16 Media Converter Switches.