About this 3D model

Here's what I did for the contest, it is a keychain that is used in millimeters from 0 to 20 mm which prints in about 15 minutes which is rather fast as a test piece and can be used at any time after printing because there is no need support, you can transport it to your keyring and especially you do not need to have a meter or a ruler on you because you with a keychain that can check the thicknesses for example, etc ... .. LIFEHACK3D