D-Link Power Supply DPS-500A 140W 

The DPS-200A, and DPS-700 redundant power supplies (RPS) are designed to conform to the wattage requirements of D-Links Fast Ethernet and Gigabit switches. They provide a low-cost, simple solution to the problem of a failure of the internal power-supply of an Ethernet switch, which can result in the shutdown of that switching device, the devices attached to its ports, or an entire network. Supporting full output power for the switch, these redundant power supplies can maximize the availability of the switching device.