Yeah, the ones that I got were from Neu's website. They also sell, what they call, battery side connectors. The example that they showed was their use on a sub C cell, but I've wondered if those can be soldered to the Mamba Max onto the solder pads for the esc to motor connections, or even the battery to esc for that matter.

What's really nice about them is that they are only about half as long as the 4mm connector, making dealing with routing the wires a bit easier.