MGN12 Linear Guide Rail Guide 400mm with MGN12H Bearing Steel Carriage Block Bearing Steel Sliding for 3D Printer and CNC Machine (Black H-Type)

Seems to be flawless only complaint is it be nice if they locked the carriage in place some how so it didn't slide around on shipping.

Rail and bearing is fair quality. Wiped it down directly out of plastic and paper towel was covered in rust. Black color makes it hard to tell it had rust on it. Luckily for my specific application it will be fine. If I had bought this for a 3d printer I would have been very upset.