With the GoPro Head Strap + QuickClip, you actually have 2 mounting sets in one. The head strap is very suitable to mount to your head or helmet, so you can record all your sports actions right from your point-of-view. You can mount the QuickClip to a cap or hat, or to any other object that's between 3 and 10mm wide for a compact attachment.
Tip: as the name suggests, the QuickClip is quick and easy to mount to the head strap or a cap. Please note that this QuickClip can easily come loose during activities such as bungee jumping, skydiving, and diving in water. For these activities, it's better to mount your action camera to the head strap with a thumbscrew. This'll keep the camera in place better.