If you, like me are fed up of having to shield your viewing eye from the glare of the sun whilst trying to frame your shot this eyepiece is for you. Yes it's expensive, but the photo doesn't do it justice. It has a deep cup that totally shields your eye from glare and distractions from your wife (who may, or may not be tapping her foot in boredom as you frame your 'David Baily' for a forth time! I am delighted with the results and don't regret spending the money one bit. Some comments suggest that it works loose and can be lost from its attachment, but I have found it to be totally secure and it has resisted my attempts to artificially knock it loose. if you buy this eyepiece you won't be disappointed. Happy Snapping! Mark.