Review on Iverntech MGN12H Linear Rail Guide With Stainless Steel Carriage Blocks - 700Mm Length For 3D Printer And CNC Machine by Marcos Olvera

I used these to make a custom corexy printer, and they are running smooth. I purchased 3 of the single-carriage 450mm size, and all three came clean and running smooth. I previously had other knockoff rails that cost less, but the old sets didn't run as smooth, and eventually started binding. These have been running longer than the previous set and are still running smooth.They were also well packaged; in undamaged plastic sleeve, and held between foam ends. Be aware of the couple of extra ball bearings in a small bag stapled to the plastic sleeve. Keep the red plastic bumpers around and use them to keep everything together if you need to disassemble.