Adjustable Face Shield Strap (TPU Flexible Filament)

It is hard to find elastic bands now. So I tried to design some 3D-printable straps using my TPU filaments. Then, I found gnome053's design and gave it try. It works great; but it is a bit slippery at the buckle. So I went to Fusion 360 and resketched the whole thing and added a few bumps to lock the two pieces together. At a thickness of 0.8mm-1mm, it works well. One would need to squeeze the buckle a little bit to adjust the straps. Once locked int, it is pretty secure. TPU filaments tend to be sticky, so I added a few shallow grooves to allow the extrusion to smooth out. They are pretty strong and flexible and can be washed for reuse. Update 1: Added 3rd version with 12 holes and a stopper. It is easier to adjust. Update2 : Added a 4th version with corrugated straps for small printing bed (< 140mm). Each stretches to about 210mm. It takes longer to print and requires a bit of cleaning in my experiment. Print instructions I have printed a few sets at 15% infill, 225 degrees, and 0.2mm.