This set of 3 flexible helmet mounts from K&F Concept immediately makes a sophisticated and robust impression. The base is made of flexible TPU material and is significantly larger than classic GoPro adhesive pads. As a result, it adapts better to curved helmet shapes and offers significantly stronger grip, exactly what you want for sports activities such as skiing, MTB or motorcycling! The adhesive surface is absolutely secure and gives you noticeably more confidence than many standard solutions. I have not yet tested them in practice in wind and weather (only when the sun is shining), but the workmanship and the generous contact area suggest that they will last reliably even under load. The 180° swivel module allows precise adjustment of the shooting angle and makes creative perspectives easy to implement. The scope of delivery is also positively noteworthy: 
In addition to the adhesive pads, there are matching 1/4 inch adapters and screws, making the set easily compatible with Insta360, GoPro or DJI action cams. 
Everything looks solid and well coordinated. According to the manufacturer, residues are not expected when removed, which will be seen the next time you use them. My conclusion: 
Anyone who has ever lost or damaged classic helmet mounts will immediately notice the difference. These brackets offer more space, more grip and more flexibility. For me, a well-thought-out upgrade with high suitability for everyday use.

 4 out of 5 stars, as long-term experience is still pending!