6 PCS 8mm x 11mm x 22mm Linear Brass Bushings for RepRap 3D Printer Prusa i3
These are great replacements for LM8UU linear bearings - quiet and effective, very low friction. You need to use polished linear shafts for the best performance. These are longer bushings, and we have also have similar but shorter brass bushings in our store.
See attached drawing for bushing dimensions and details.