Beware- you are only getting one lens, not a set (think Col. Klink!). Furthermore, it is a real "stretch" to think you will get this lens swaped out with the standard one without any troubles. The instructions are printed on the box but are a little confusing since the accompanying pictures are too small to see any detail. I gave up after three tries and sent my "monocle" back. Oh well. I hope you have better luck! It is great idea, just needs a little refinement.
Eagle goggles fit nicley. Great to see while swimming. Interchangeable lenses. Too bad this product line is not being carried.