These are rain tires for the excellent OpenRC F1 printed out of the super soft Shore 85A Durrometer Ninjaflex material. These tires have deep grooves for maximum traction on all road surfaces and are printed completely hollow for maximum contact with the road. Sold in sets of 4, these are all the same size of tire.
They are printed using a custom Flexystruder and 0.8mm diameter E3D hotend. For each set of tires sold the Colorado Printing Project will tip the creators of both the Deep Groove Rain Tires as well as the OpenRC project as a thanks for their contribution to this awesome open-source project.