The My Book 4 TB external hard drive from WD gives you the freedom to carry, store, as well as protect all your important data on-the-move. Just connect the power and plug it into your computer or laptop to instantly add more storage space to your system. Automatic Backup Software This external hard drive effortlessly works in the background to protect your data by keeping backups automatically. Password Protection for Encrypted Privacy This hard drive allows you to create a password to protect your data from unauthorized access. Universal Connectivity Equipped with USB 3.0 connectivity, this external hard drive ensures ultra-fast file transfers and can be connected to almost any USB-enabled device.