Finger car toy
thingiverse
This is toy for concentration training. You can try draw race circuit on paper and than try race without going out of boundaries. There are tree designs in my opinion is 27.5 the best.
Download Model from thingiverse
With this file you will be able to print Finger car toy with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Finger car toy.