A confusing title I know but they are call different things with different manufactureres. I have noticed recently that the majority of these 'enhancers' are a real struggle to fit on the scope eye piece. I use a Bisley version, could not get on with the other ones. So my question is are there any out there that will fit on the eyepieces that are not such a struggle to fit. Ideally I am after one that has a slightly larger diameter (about 5 to 8 mm) that is similar to the Bisley one that would fit on my Mk2 Nikko. Someof my club are also thinking of changing theirs if they can find a suitable one.