I have been looking all over for a simple connector, that all of you have seen a thousand times

I had some sent to us for a solar panel project, and they worked great to interconnect the panels. But I just can not seem to find any that are like them. I can find all sorts of light duty ones. 16ga etc.
The ones I got and now need are like 2 feet or so in length,, and HEAVY wire. 14 Min 12 preferable.
Obviously they were made, because I have 4 sets of them in use now. But online all I can find is short length and light ga wire versions.
Actually any type of cheap polarized connector semi weather resistant will work.
suggestions?
Thanks