About this 3D model
it looks like there is a strap missing for this project so here is my suggestion for one heat the strap with a hairdryer and make it round ( or fit it to your head ) made with tinkercad by kttjdesign tinkercad beginner guide : to anyone who wants to know the basic actions of tinkercad. Everyone can learn how to make a 3D figure tinkercad beginner guide, you can do it also