Under FAA AC 70/7460-1M, the A0 tower type is 150′ tall or less. The structure should be lit by at least 1 red/infrared LED steady-burning double L-810 obstruction beacon. Infrared LED strings must be monitored, and an IR outage is a NOTAM-worthy event.
FAA AC 70/7460-1L and earlier FAA advisory circulars do not require infrared LED output and monitoring of IR strings.
Each of the solutions below offers an OL2 variation for A0 tower lighting.