Review on Uxcell Straight Connector Aluminum Extrusion Industrial Hardware and Brackets by Carta Gutierrez

I've bought enough of Uxcell to know what "quality" to expect. However, in order to use them, you need to clean the edges of the threaded holes. I also had to sand and sand the edges and ends a bit. Once I had them straight and functional they did the job. But if you want tighter tolerances, you might want to avoid them (or just glue V-slot sliding nuts, lol). But for $5 they get 4 stars. A little more expensive and 4 stars would be undershot.