Review on Chanzon 25Pcs 1W 3W 5W LED Heat Sink (2 Pin Black) Aluminum Base Plate Panel PCB Circuit Board Substrate 20Mm Star DIY Heat Sink Cooling For COB High Power LED Chips Lamp Beads 1/3/5 Watt by Matthew Carr

Yes it is true they are easy to solder, but they have two minor flaws and a big one. First. There are two of the six soldering spots that are intended to be the diode soldering spots. You realize that after you have 4 or 5 diodes soldered on the spots are not the right ones. Why not a picture or a draw inside the package?. Second. When you put the diode on the heat sink you loose the +- marks, because they are bellow the diode, you can just see a little pars of the plus or minus and need to guess which one is + or -.The big one. They CAN'T dissipate 5 W. I made a series parallel circuit in which each 5 W diode dissipates 1,6 W. With that energy, the temperature stabilizes at 57 *C in 17 minutes. If I change the circuit in order each diode dissipates 3,4 W, the diodes reach almost 70 *C in two minutes, that will burn them in minutes.