A rubber eye cup keeps stray light from the viewfinder and is especially useful for eyeglass wearers. This model fits all professional Nikons with round Okularanschlüssen. For there is a small rectangular plastic adapter that can be snapped. In addition to the eye cup but we still needed a cover glass or a Augenkorrekturlinse. Their flat rubber ring is removed and replaced with the eye cup. A deferred from behind metal ring prevents jumping away of the gum. The cover glass has been used to love solved by itself. In the more modern cameras, there is a detent that is only unlocked by closing the eyepiece, a small but very well thought-out detail. An eye cup is a typical wearing part. Every now and then you have to replace them.
