Just bought these from Space Hi-Fi and connected two 10 gauge stands together for each cable. These connectors can take very, very large cable easily, are very solid construction and takes a cable to professional level.
The plugs do something different to all my other plugs: they plug into the amp sockets and then you tighten the barrel of the plug, which expands the tip and locks them into the plug socket - connection is rock solid.
I've actually noticed a difference using the Space Hi-Fi connectors, in that with larger connectors and cable you get more power to your speakers at lower volume levels and a wider and deeper sound stage.
When I need more plugs for bigger home made cables, I will be getting some more from Space H-Fi, as they are local Australian and their postage service is super quick.
My rating is better than good: excellent.