Hotswap Bays and Trays. These come in three different packaging:
Complete Bay+Tray - This is the mobile rack plus drive
tray together. Standard (LED Lights) version. Includes
drive and bay installation screws plus tray locking key.
Tray Only - Standard LED versions. Includes screws.
Replacement Bay Only - Drive bay without tray. This is a
replacement part. Standard LED version.
Trayless Bays - complete bay that accepts bare drives without
any tray. Accepts SATA drives. Insert the drive - connector end first, close
the door and it makes the connection. Open the door it hands you the drive.