I bought two sets of these to put into a long shelf with an overhanging lip on top. Each set came with two rails with holes drilled all the way through and two rails with a recessed hole. The holes for the fully drilled rails matched each other and the holes for the recessed holes matched each other. But they didn't match their opposite number. There were no instructions with the product or on the web site,, but I assume that the recessed rails are supposed to be on one side and the ones with the holes on the other, so that you can secure one set and then slide the other into place over the dowels. I had to modify the set up to make it work, and it took four times longer than it would have if the holes had all been drilled/pressed correctly. The materials are good quality, the oak was very hard and solid. It looks good and was an okay price, but QC was not paying attention. I saw another commenter had the same issue.