The Quadruple USB 3.0 SATA HDD Dock allows you to plug access 2.5" or 3.5" SATA Hard Disk x 4 to your computer via USB port at the same time. Each SATA Slot supports up to 8TB, total support 32TB. It's a powerful tool for data transfer, backup and cloning. The device is compatible with both PCs and Mac.