Nimitz 2nd HDD SSD Hard Drive Caddy for ASUS Ultrabooks Replace 9.5mm Optical Drive Add a 2nd drive to your laptop by replacing your optical drive Mounting screw-holes on caddy provided so you can transfer your original optical drive's mounting brackets to the caddy Comes with a flat faceplate and a special faceplate(fits A46/E46/S550/A450 series,may not be perfect for other series,but you can transfer your original optical drive's faceplate to the caddy) Works in optical drive bay of ASUS Ultrabooks Caddy installed (in A550) as picture #7