If you want to mount this flash light on your helmet with a GoPro base:
https://amzn.eu/d/1KDS1O8
You can use a rubber if it is not tight enough.
It is an additional mount for this one:
https://www.printables.com/model/873989-mtb-flash-light-holder-for-a-diameter-of-25mm<
Support: No
Material: PETG or PLA
The author marked this model as their own original creation.