I have finned heatsinks on my HLG’s. I think they can be ordered both ways.Ahh. I thought the heat sink WAS the board on those. I have an HLG 100. The board is metal and gets warm. The only parts are the board with the chips on it, the driver that generates the warmth, and the hanger. I'm curious whether the driver could be made digital, much like HPS ballasts. and become heat free. The bane of growing....My tent got hot last night.