I bought a BougeRV MC-4 tool set with 4 connector pairs. This was my first time actually crimping together my own MC-4 cables. I also bought #10 AWG solar cable, so it really fills up the crimp terminal, and barely fit through the connector cap. The crimp tool seems to be decent quality and made nice tight good looking crimps. The connectors with the crimper are not the best quality, but they fit together well. My only concern is that I felt the pin and socket terminals seem to fit pretty loose into each other. I expected the fit to be a bit tighter. It was consistent with any of the 6 pins with any of the six sockets. There is a lot of contact area, and when I checked it at 5 amps, the voltage drop across the connection was minimal and no heating. Most of the connections in my array will never top 5.5 amps, and only the connection after the parallel "Y" will hit 11 amps. And the "Y" cables I got fit both the pins and sockets of the BougeRV connectors a bit tighter. I noticed those sockets were not complete circles like the Bouge ones, there is a gap, and the shell was a bit "springy" so it grabs around the pin with more drag force. Once I inserted the pins into the plastic hoods with the O-rings, I could not feet the drag difference of the pins, the force to push the O-ring into the other side of the connector is more force than the metal pins connecting. I checked on the connectors a few times and so far, they are staying cool, well, as cool as anything else on the roof. They are all under the panels out of the sun, and felt about he same temp as the roof under the panels in the shade. I really need to get a thermal camera to really check things out better.