The 2-Pack 2.5" to 3.5" HDD Adapter Caddy is a set of enclosures made from Acrylonitrile Butadiene Styrene (ABS) that allow desktop hard drives with a 3.5-inch size to be used with a 2.5-inch adapter. This caddy provides a convenient and reliable solution for adapting smaller drives to fit into larger drive bays, making it easy to upgrade or expand storage capacity in your computer system. The built-in media feature of the 3.5 caddy ensures a secure and stable connection for your hard drives.