The X-3531 is a removable HDD frame for four 2.5-inch SATA I, II, III hard disks or SSDs with standard height and is designed for installation in a 5.25-inch bay. The built-in 30-mm fans provide optimum cooling for the hard disks. The X-3531 is powered by a Molex power connector. Please note: When using this product in conjunction with Intel Onboard S-ATA controllers, the controller in RAID mode or the ports of the controller must be explicitly set to "hot plug/external port". If the settings are not available, error-free operation may only be possible with an additional S-ATA controller.