Can somebody explain how the strap works to me?
You can fasten the belt tight in case it loose from the object while you use Jaws flex clamp mount to clamp something
Is the arm flexible enough to allow you to use your phone in portrait mode rather than landscape mode? I'd like to use it for FaceTime.
The mount is okay to clamped on the desk or something round
Does the gopro hero 2018 fit this jaws flex clamp mount ?
Compatible with all hero series
Does the camera on the clamp make a lot of noise when it is moved?
It will make some sounds, slight enough to ignore. i think it acceptable.