This threaded rod is a commonly used part in constructing frames or any other machanical part of the 3D printer. The bar is made from zinc plated steel and 100 cm long. The thread size is M4.
In some cases it can save costs to use this product instead of a lead-screw for linear motion. If you use this part for linear motion, you can use PTFE spray to lubricate the rod for better motion, but note that the resulting end quality of your prints will be impacted due to the imperfections of metric rods.
If you order this product, you will get one piece of 100 cm, mostly packed in a separate package due to the size.