Shruggs....I dont really know and he is back on another assignment in chicago. He will be stopping by my house on his way back to eastern Pa. I will ask him to clarify. All I know is he is a computer wiz who spends more time analyzing stuff than I have free time in a day. He usually is on point with most of his info but again I have not tried it. He just told me that if I began using a 1000 watt HPS then I should purchase this. I can always have him use my name on the computer when hes here...that way I cant screw up the details. All I know is he had several 1000 watt lights going when he lived in Indiana and he swears by them....but Im a novice....I was just passing along the info...But I will ask him to clarify. Sorry for any miscommunications on my part but all I remeber of most of the convo was 300 to 400 bucks for one.... and that the system reads like a computer to the electric company. Yadda Yadda Yadda blah blah blah....I will ask him and get a more complete answer! I will post it as soon as I can