The Transcend StoreJet 25H3P Series is approved by the US Military drop-test standard (MIL-STD-810F). It is built with a triple-layer protection to ensure your data is safe even if the drive is accidentally dropped. This drive is powered by the USB port on any PC or laptop, which means no external power is required.The StoreJet 25H3P portable hard drive is a powerful storage device that combines superior performance of USB 3.0, 4TB of storage space that can store about 300 DVD movies, and a three-stage shock protection system that meets rigorous U.S. military drop-test standards. With transfer speeds up to 90MB/s, StoreJet 25H3P is an ideal option for speed lovers. Imagine transferring an entire DVD movie in less than a minute!Besides incorporating a brilliant purple anti-slip rubber enclosure, the StoreJet 25H3P includes a reinforced hard casing that evenly distributes the force of an impact, and an internal hard drive suspension damper as a last line of defense. It is also equipped with an extremely convenient OneTouch auto-backup button, which lets you instantly backup and synchronize data with your computer.