It was used in a gravel plant. Nearby building materials store and home center - there are only small things with screws, so we ordered it here. We welded in two sets of upper and lower. But I was planning to order by consenting it for right and left use, but it was the opposite. I wanted to attach it to the left side of the door, so I asked for the left side, but it was different. As amateurs could understand, I thought that they would explain with illustration etc.