The unit is switched on by turning the lens clockwise and anti- clockwise for off. As InfraRed cannot be seen with the naked eye, a short pattern of audible beeps upon turning the beacon on, confirms the beacon is operational.
Using quality alkaline batteries, 6 beeps indicates the batteries are fully charged. 3 beeps indicates the batteries are part-used. 1 beep indicates the batteries are very low and should be replaced. Being InfraRed, there is no visible Low Battery Indicator.