Our 1, 2, 3 and 4 compartment feed bins are all made in the same way, they all have a raised base so the bottom of the feed bin doesn't rot away, all the edges are double folded so if fingers are inadvertently shut in lid it won't be a raw metal edge cutting into them this also provides a lot of rigidity to our storage bins. We use a locking stay with our lids so when you open the lid it won't fall back down on you and our fitted locks make our storage bins look fantastic in any stable/feed room.