Bearing for lead screw of 8 mm diameter. The part fits to a 20x20 aluminum extrusion profile with 6 mm gap. Is fixed to the profile with M5 x 16 mm screws, a ring and slide nut. The part is designed for a 16 mm OD and 8 mm ID ball bearing of 5 mm thickness. Printed at 70% fill this gives a very sturdy connection. Perfect to have low cost build of CNC machine or 3D printer. STL file needs to be scaled 10x for printing.