Mirrored Drive Doors
Apple 922-5290, 805-3783. Dual Hard Drive Carrier for the Power Macintosh G4 Mirrored Drive Doors and FW800 models.
Plug and play carrier for 2 hard drives, just slides in and out of the case. Note that this works in both hard drive bays - vertically on the far side under the power supply and upside down under the optical drive carrier.