VisionTek's DriveXpander will help you add more storage to your old Mac Pro

The DriveXpander is compatible with both hard drives and solid state drives between 7-9.5mm in height. You can use the adapter to get quick access to your drive, and quickly add it to any PCI or PCIe expansion slot (the slots on the back) or hot swap it with a new drive if need be. The DriveXpander also secures your drive from unauthorized physical access with a lockable drive access lever.

You can find out more from VisionTek at the link below. The DriveXpander is available to order now for $19.99.

Source: VisionTek