Power-conserving WD AV-GP SATA hard drives take advantage of WD s GreenPower technology to meet the extreme requirements of demanding audio and video environments. With power reduction of up to 40% they deliver cool and quiet operation and reliability perfect for audio video applications such as PVRs DVRs Set-Top Boxes (STBs) as well as surveillance video recording. Form Factor 3.5 x 1/3H. Interface Type Serial ATA-300. Data Transfer Rate 300 MBps. Buffer Size 16 MB. Approximate Dimensions (WxDxH) 4 in x 5.8 in x 1 in. Capacity 500 GB.