A few days ago someone said they were having a hard time building their coop so it would be square. I mean, the corners weren't matching up when they put the last panel on. I found these on the internet the other day. My coop is built, but it looks like it could go a long way to making the coop squared off easily. If I build another one, its very possible I will use it. I'm not saying this is all you would want to use. I would throw some screws in there and tighten it up. But, for those who are doing their first DIY project, or even just people who just want to make it simpler, they could be a useful $15 spent... I have no affiliation with Amazon or the manufacturer.