The model 3120 employs two separate color LEDs to indicate battery power results in green and voltage check decision results in red. By displaying these two functions with different LED colors, the instrument status is apparent in a glance. Battery status can be continually indicated when the unit is on, by having the green LED always lit. You can also activate a switch to minimize power consumption by disabling the green LED when not in use.

The 3120 was also designed with special attention to safety, as well as satisfying CAT IV 600V safety requirements. Luminous decision results are supplemented by the audible beeper, so that the reliable checking can be conducted even in harsh environments where the visual indication may be obscured.