The file 'GoPro Knob For Hex Bolts (parametric) 3D Printer Model' is (stl,f3d) file type, size is 802.1KB.
A (parametric) recreation of the GoPro knobs to be used with standard length hex bolts. STLs are provided for M5x25, 30, 40, and 50 hex bolts (the picture with 6 knobs includes the standard two GoPro lengths for comparison). If you have a different length you want to use, you can use the Fusion 360 file to change the "totalHeight" parameter which should be 10mm less than the bolt you are using to get the proper amount exposed threads. This also is close enough to the real thing that all of the "wrenches" I've tried have worked to tighten it on a mount, albeit a little tight.
If you are looking for the dual GoPro mount pictured above, you can find it here: https://www.thingiverse.com/thing:2367978
GoPro_Knob_-_15mm_-_M5x25.stl | 573.5KB | |
GoPro_Knob_-_20mm_-_M5x30.stl | 467.5KB | |
GoPro_Knob_-_30mm_-_M5x40.stl | 337.3KB | |
GoPro_Knob_-_40mm_-_M5x50.stl | 354.0KB | |
GoPro_Knob_v3.f3d | 184.7KB |