iStarUSA Group 3x5.25" to 4x3.5" SAS Cage Silver Trayless (BPN-DE340SS-SILVER) Aluminum frame, light weight and durability design Tray-less and screw-less HDD mounting Aluminum front bezel with metal Key lock mechanism for security Integrative Shaping aluminum design for quickest heat sink Supports hot-swap & RAID configuration (additional RAID controller needed)