I have a Kessil A360 light controlled by the Apex. The kessil cable attaches from the V1/V2 port on the Apex to the Kessil input jack. The cable is sold separately from the light. you can daisy chain multiple kessil lights together that will be controlled by the apex depending on how large a tank you have. You program the brightness & color intensity ramps for dawn, dusk, moonlight, etc.. I like it so far.