Yeah, I've got those on a few scopes but they always wind up breaking on me and finding clear ones in the right size is a pain in the neck. Plus, if you don't secure them well, they like to fall off when pushing through brush or if you bump them a certain way.
I like this style the best, simple, and won't fail. they just slip on but you can see through them, most of them are rubber and are opaque though. Can't seem to find anyone who makes/sells the see-thru kind I like.
Nothing to break on them, no noise as with the quick flip open covers produce a fairly audible pop not to mention you can take a shot quickly if you have to as is. If you get time, then you can easily slip them off and have a nice dry, clear scope.
It can fog up underneath them still (although pretty rare) but no more than the regular flip up caps. Why doesn't anyone make these?
Maybe I should start making them and selling 'em...