Feature: 1. Support standard 2.5-inch SATA hard drive and CD-ROM for 9.5 mm SATA bit interface 2. Using SATA3.0 technology, the speed can reach 6Gbps, the specific operation depends on the channel standard of the optical drive on your machine motherboard 3. Fast and reliable connection just like the main hard drive. Fully integrated into the laptop, no cables/psu/software drivers required 4. Dual boot, support to install the second operating system on the second hard disk and select boot 5. Compatible with laptops with 9.5mm thick DVD‑ROM, very practical Specification: Item Type: 2nd SSD HDD Caddy Support Hard Disk: 2.5 HDD, SATA, SATAII SDD Compatible Model: Laptop with 9.5mm thick DVD-ROM Applicable Models: For OS X Book/OS X Book Pro and the following models for OS X notebook/iOS X with optical drives: MD101/MD102/MD103/MD104/MD313/MD314/MD311/MD322/MD318/MC724/MC700/MC725/MC723/MC721/466/467/470/471/985/990/991/207/371/373/374, almost all models produced on and after 2009. Package List: 2 x 2nd SSD HDD Caddy2 x Screwdriver2 x Screw Pack Note: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.The size of the heat dissipation hole is shipped randomly. The hole position is for heat dissipation and does not affect the use.