Iomega 33991 eSATA/FireWire 800/FireWire 400/USB 2.0 500GB UltraMax Hard Drive Device Type - External Dimensions WxDxH - 5.5" x 9.45" x 1.63" Removable Storage Type - Hard Drive Dimensions WxDxH - 5.5" x 9.45" x 1.63" 8MB Cache Buffer or higher