WD AV-25 2.5-inch SATA hard drives are specially engineered to offer cool quiet operation while providing maximum reliability in 24x7 always-on environments. With support for up to five simultaneous HD video streams, these drives are perfect for DVRs, digital video surveillance and other demanding multimedia applications. 3-year limited warranty. These drives are designed to last in always-on streaming digital audio/video environments such as DVR/PVR, digital video surveillance and other demanding multimedia applications. Advanced Format technology delivers improved video quality and AV performance through enhanced error correction capability. Optimized for smooth, continuous digital video playback of up to five simultaneous HD streams. SilkStream is compatible with the ATA streaming command set so AV customers can use standard streaming management and error recovery option. A cool drives is a more reliable drive. WD continues to develop new and innovative ways to keep drives cool while they are operating. Noise levels have been minimized to virtually below the threshold of human hearing. The drive draws less than 2 Watts while operating and a mere 4.75 Watts during spin up. The drive arm frequently sweeps across the disk to reduce uneven wear on the drive surface common to audio video streaming applications.