| Amber | Amber LED Displays |
| Blue | Blue LED Displays |
| CW | Ceiling/Wall Mount Bracket; Optional for ES-272U/6, but CW comes standard on all ES-272U/9. |
| DC | DC Operation: Requires the unit to be powered from a DC source exclusively, typically +12 to +35 VDC. |
| Green | Green LED Displays |
| J | 220 VAC/50 Hz Operation: The unit is configured to operate from 220 VAC line voltage. 117 VAC 50/60 Hz is standard. |
| NTP-C | NTP Client: NTP Client Displays synchronize exclusively with an NTP server (replaces all standard inputs). |
| P | 19" Front Panel (Rack Mount), this unit will be 2RU. |
| UL | "UL" Approved Power Supply: The unit is supplied with a UL/CSA approved wall mount power supply. |