Viper Key Fob Repair

My Key fob wouldn't stay together anymore so I made a belt for it/

*There is a 3mf and a stl file.
I prefer 3mf but thingiverse says
"A Thing must have at least one file of type: stl, obj, thing, scad, amf, dae, 3ds, x3d, blend, ply, dxf, ai, svg, cdr, ps, eps, epsi, sch, brd"

For more information on why I prefer 3mf see https://all3dp.com/1/3mf-file-format-all-you-need-to-know/