From my experience, the use of any see through scope cap defeats the purpose of buying good glass. And the use of the flip up caps add too much to the diameter of the ocular and objective bells, interfering with the field of view. Why spend sometimes a couple thousand $ on glass and then cover it with a <$10 cap? I understand in some conditions caps are needed in extreme hunting situations (I do not have access to hunt those places), but in first 20 of 40+ years of hunting, I tried just about everything that came out that had anything to do with hunting (I probably have 15-20 pairs of BC see through or flip ups sitting in a drawer) and figured out the scope cover method was best for me. As mentioned in another post, in extremely bad weather I do keep a BC bikini in my pack.