Original GoPro Jaws are expensive. They come with gooseneck and costs 49.99$. There is much cheaper solution.

Buy a plastic spring clamp in hardware store, they cost around 5$, a screw that is same width as GoPro screws and small GoPro connectors from eBay, They cost around 1$.

Most of them already have hole in the end, if not, just drill one by yourself. Attach small GoPro connector with screw, you might want to put some washers in gap between connector legs, or just crush it when tighten screw like I did. And thats about it, now you own pretty strong Jaws flex clamp. If you are lucky enough and find clamps with flat surface, you can stick adhesive mount on it, and buy gooseneck off eBay for 10$, unfortunately I had only clamps with round handles in hardware stores around me and I had to attach small connector with screw.

Finished product and finished product in action