Looking for decent (but not ridiculously priced) flip-up scope covers. I have a Leupold VX-3 3.5-10x40 and a Burris 3-9x40 Fullfield II. (And before anyone says it, there's no way I'm paying close to $100 for a Leupold cover!) I'm just looking for something that will get the job done and keep dust and dirt out of the lenses. I don't expect them to last as long as the rifle -- but a couple of years of use would be fine. Appreciate any inputs on gear that works -- and how close the tolerances are. I've seen some caps that fit a "range" of eye or objective diameters -- but they end up covering part of the lens and reduce the sight picture. I worry about some of the brands that I see that have very specific measurements (39.9mm instead of 40mm) and whether there is any "give" or if it's an all or nothing fit. General advice or specific recommendations on brands that work with the scopes I mentioned are appreciated!