The Western Digital Caviar WD400 3.5-inch WD400BB-75AUA1 is a hard disk drive with a form factor of 3.5 inches, making it suitable for use in desktop computers. With a rotation speed of 7200 RPM, this HDD provides fast data transfer rates. It is designed for use with IDE interfaces and offers reliable storage for your files and programs. This Western Digital drive is a dependable choice for expanding the storage capacity of your computer system.