SWAROVSKI OPTIK Angled Eyecup (One) f/ 8x30 WB SLC Mark III Binocular

Swarovski Angled Eyecups are great for when you're not wearing sunglasses or eyeglasses; you'll feel as if you are locked in to the view, like watching a movie in a completely darkened room.

As the description implies, this is one angled eyecup.  You will need two of them to replace a pair of eyecups for a binocular, of course.