This is a high quality AL Heat Sink(With adhesive tape).There is a high quality of U.S. origin 3M-8810 thermal adhesive tape on the back of the heatsink.
So you needn't coat a layer of heat conduction glue on the heatsink,Just remove the blue protective film on the thermal adhesive tap and then stick in the
desired chip parts.Viscidity is very strong.
Notice: Make sure the surface of the component is clean before sticking the heatsink.
This heat sink can be used with stepper motors, motor driver board and so on.