Dell PowerEdge T420 Owner's Manual page 12

Item Indicator, Button, or
Connector
Figure 3. Front-Panel Features and Indicators—3.5 Inch Cabled Hard-Drive Chassis
NOTE: Cabled hard-drive systems are not rackable.
Item Indicator, Button, or
Connector
1 Tape drive (optional)
2 Optical drive (optional)
12
Icon Description
• Up to sixteen 2.5 inch hot-swappable hard drives
Icon Description
One optional 5.25 inch tape drive.
One optional SATA DVD-ROM drive or DVD+/-RW drive.