Those green area lights are from Kill Light. They have a three-position switch. There is OFF, and then there is ON -- and between there is a setting that has the light come on a bit dim at dark and then build up slowly to full brightness. They take 4 C-cell batteries and will provide light all night long for well over a week.
They are designed with rings and magnets on the back for mounting them on the bottom of a standard feeder. With a little wire or para cord it is easy to hang them if there is no feeder around.
They really work well.