About this 3D model

Since the outbreak came to Spain my grandma started sewing masks, but the straps' length didn't always to the mask's users. I saw on the internet small pieces that adjusted the straps to make the mask tightened to the face, but i decided to design my own ones, that are easy and fast to print. The inner diameter on the top is 2.5mm long. This is works fine for the straps I've tried on, including the surgical mask straps. If you want to edit it, I've uploaded the Fusion 360 and .dwg files also. Since they print inmediatly I recomend to use low layer heights, they seem to be stronger.