ClyxgsAluminum Water Cooling Block, Liquid Cold Water Plate Heat Sink Water-Cooled Exchanger Head semiconductor Refrigeration Sheet CPU Graphics Radiator Heatsink Endothermic Head (40 x 200 x 12mm)

Im using this water block to cool a 100 watt LED module that will be mounted in a closed enclosure.It is working very good.My only complaint, the surface of the block was rough. I polished with 2000 grit sandpaper for a very smooth finish.. better heat transfer.

Esta perfecto

I don't think it will matter a whole lot in most cases if you use thermal paste, but you will want to sand these to at least 800 grit for better results, and higher if you're not using thermal paste or these are for a high power application. They came basically with a finish that of wood, but I sanded down to a near-mirror finish (even though not totally necessary). Due to the very basic fabrication skills, there are no internal fins or anything, but they should still be good enough for a good number of applications due to how conductive aluminum is at this size.

very good