"The Western Digital My Book has been around for a few years and has several versions in its product line. Prices range from just under 100 Dollars for the My Book Essential 160 GB to just under 600 Dollars for the Studio Edition 2 TB and features eSATA, USB 2.0 and FireWire connections.
Today we are going to take a look at the Mirror Edition, a dual drive external product that is available in 1 or 2 TB capacities. What makes the Mirror Edition unique in the over saturated external drive market is its ability to store data in RAID 1. The Mirror Edition in RAID 1 stores your data on two drives in full, giving you two copies of everything. Since hard drives can unexpectedly fail, rendering them and the data stored useless, it is important to keep a back up of the data you never want to lose."