The Neptune, Neptune 2 and N3 have an electroluminescent backlight to be able to see the display in low light conditions, including night jumps.

If the backlight is enabled, when you are on the ground or in the aircraft the backlight will illuminate briefly whenever you push a button (it does not stay on to conserve the battery). When the unit detects that you have left the aircraft and switches to freefall or canopy modes the backlight will stay on until the unit returns to ground mode.

It is important to note the following:

- The backlight drains the battery at a much greater rate than normal operation, make sure you use a fresh battery for night jumps.

- The Neptune and N3 are primarily designed to be used as a visual OR audible altimeter. The unit will not support both the backlight and alarms being active at the same time. For safety reasons the alarms are given priority.
If you are using the unit as a visual for a night jump, make sure your freefall and canopy alarms are disabled.
(If the alarms are not disabled, the backlight will go out during the period that an alarm is sounding).