FEATURES- Serieal ATA RAID Drive Cage
       Internal drive expansion cage that supports 4 hot swap drives in a
        3 drive space to maximize storage capacity and minimize space. 
* Compatible with Serial ATA 1.5Gb/s and Serial ATA 2 3.0 Gb/s 
* Require 3 standard 5.25" form factor slots 
* Support up to 4 3.5" hot plugging ATA or Serial ATA drive trays with
  key locks.
* Accommodate 4 1" height disk drives 
* Back plane design 
* Built-in fans for self-contained ventilation 
* Individual hard drive power and activity indicators 
* Front access design to facilitate hot swap 
* Key locked power management for reliable hot swap

Internal drive expansion cage that supports four 4 Serial ATA SATA hot swap drives in a three 3 drive space.