Designed to enhance your Noctivid binocular viewing experience, this pair of Leica Winged Eyecups replaces the stock conventional eyecups quickly and easily without tools or modifications to the optic. When installed, the eyecups block peripheral light from interfering with your vision to improve clarity and contrast, while also blocking distractions to give you an immersive observational experience. If don't want to use the wings because of sunglasses or other eyewear, the angled portions simply fold back out of the way. A new one-piece rainguard is included that is made to accommodate the winged design.