This is a model to test and calibrate retractions on your 3d printer. in case you do not know what retractions are, they are a setting for 3d printers that you can ad when you slice the model and it pulls the filament up from the nozzle and releases the pressure, getting rid of stringing,this is to calibrate that setting. The more milimeters you put as a retraction the more presure released but also the print time goes up. Make sure to check out all the makes.

(PS: This can be used for different materials like Carbon fiber(black),wood filled(brown), And PLA (white)