OUYANG 2PCS V Slot 2040 Aluminum Extrusion Profile 7.87 in European Standard Anodized Linear Rail for 3D Printer and CNC DIY(Black, 200mm)

Straight, true and flawless, just what's to be expected in an extruded aluminum rail. Ends are flat, finish is slightly glossy. Packaged very well with each piece separated by craft paper, then the the set was bundled and padded.

Usually when I buy aluminum extrusion, it's covered in clear tape, with metal dust inside and a sticky residue (after removing the tape) outside. This is not like that. Both pieces came wrapped individually in heavy kraft paper, and then both were wrapped together in a heavier paper. Very well packaged, no evidence of the manufacturing process (no metal dust). The ends are perfectly square; anodization is flawless, channels are smooth.Particularly if you care what your project looks like, these are an excellent choice.

These come simply but individually wrapped to prevent marring. They have flawless fit and finish, dimensional and cut to proper length. Be aware that the 2040 version is only two sections, whereas the 2020 come as a set of 4. I don't know what would make them any better or worse than any other brand, so I would buy based on price, availability and other's recommendations.

I ordered 4 packs of 2 2040. I had spent hours designing, printing and correcting a connector for it. The first pack of 2 was great, a couple small corrections and I felt I could breeze through the rest. But, the remaining 3 packs were missing the slots on the 40mm side and had some piloted screw holes. Either I could roll the dice, return it and hope the others would not have the same issue or just redesign. I went ahead and used it because I saw the other reviews commenting that they received the same thing. Fortunately, I could put this side inside the door panels, but it was a major pain.I have ordered this same brand of 2020 and it was perfect.

I've bought quite a few of these over the last 6 months, and what keeps me coming back is that they're clean right out of the packaging. No funky tape that kinda sorta catch the metal shards from cutting, these are 100% clean. Every 4 pack is wrapped in paper in a way so the extrusions don't rub while shipping, and then, they're packing in a bubble bag. If I have to gripe about something, it's that the center hole doesn't appear to always be consistent in size. I like buying the same things repeatedly so that I know it all works together. The little caps I get fit extrusions from another manufacturer consistently, but not from here. Sometimes I need to glue them in, else they'll fall out with little to no handling. Given the cleanliness though, I keep buying these.