Western Digital AV Hard Drives 500GB

• Long-Term Reliability – With a MTBF of 1 million hours, these
  drives are designed to last in high temperature always-on streaming
  digital audio/video environments such as PVR/DVR, DVR recorders,
  and surveillance video recorders.
• Quiet – Noise levels have been minimized to less than
  one sone* – virtually below the threshold of human hearing.
• Low Power, Cool Running – WD AV drives deliver best-in-class
  low power consumption for reduced system power requirements
  and increased reliability.
• Compatible – Tested for compatibility in a broad range of
  AV products including set top boxes, DVD recorders, and
  mainstream surveillance systems.