Designed exclusively for their Pure line of binoculars, the Swarovski FRP Forehead Rest provides a third point of contact on your face (the eyepieces being the other two) to greatly improve stability and reduce distracting vibration when you're hand-holding your optic. Much like a tripod is more stable than a bi-pod, adding a third point of contact ensures the binocular it held steady and securely at your eyes to greatly improve your viewing experience.
When it's installed on your binocular's frame, you have 2-axis adjustability—forward & back and up & down tilt—to custom fit it to your head, even if you're wearing a hat. There are no tools required to install or remove the rest, so you can put it on or take it off as needed in the field without the hassle of wrenches or screwdrivers.