Chain for coyote traps.
 

Morning,
I'm looking to set up some coyote traps with chain similar to the K - 9 extreme or the Bridger #3 Canadian version.
I've been searching, but I'm having troubles finding exact specs on it, or possibly overlooked it.
When you Google #3 or 5.5mm welded chain, there are so many variables including the weight it's certified for, etc. that choosing is tough. And the price varies greatly, so I want to get the proper chain, without buying too heavy a grade or something.
If someone can point me to where you guys purchase chain as well would be awesome.
Thanks in advance for your guidance,
Ken