Mig-21Spoke wheel.Grooved tire. The tire is smooth and loaded. Size 1:72 - 11 mm.Front wheel 1:72 - 6,8 mm Up to the size of 1:48, it is necessary to recalculate and adjust.Check the size in the program's slicer.Choose an STL file from Inventor or CorelCad (some new printers will not print the given STL file). Mirror the wheel in the program's slicer.The set is also in the slicer CHITUBOX. I recommend a printer with a higher resolution 10K+ HD Screen.