1. 12G Rear 2.5"x2 Drive Kit2. Hot-swappable SAS3/SATA3 Drives3. Drive Activity and Status(Fail) LED Support4. Tool-less HDD Trays5. SGPIO, Power extension Y-cable and 6G data cables are included6. Optional 12G cable CBL-SAST-0699 (internal mini SAS HD to 4 SAS/SATA) available