This is the BUFFALO external hard drive, "HD-250U2," featuring a 250GB capacity and a heat sink body. I have been using it without any particular problems since I purchased it. It has been tested to work with Windows 11 and is formatted. Please check the product information in the photos. As this is a used item stored by an individual, please refrain from purchasing if you are overly concerned about its condition. We welcome purchases from those who understand that this is a used item. - Brand: BUFFALO - Model Name: HD-250U2 - Capacity: 250GB - Connection Interface: USB 2.0 / USB 1.1 - Features: Heat sink body - Supported OS: Windows XP, Mac - Accessories: Operation guide, AC adapter, USB cable - Features: High power Thank you for viewing.