Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2777427.

This is a replacement thumbscrew for action cameras like the Akaso EK7000 and Go Pro. It's designed for an M5 x 50mm screw with a maximum screw head diameter of 9.6mm. The overall length is 38mm without the screw and 57mm with the screw fitted, leaving 19mm of screw thread protruding. The grip is about 20mm diameter at the widest part, and the knob tapers down to about 9mm diameter at the end.

The internal diameter is 4.8mm, so that an M5 screw can be screwed into the part straight off the printer.