Bought a pair of the K3 The Cyclist. They shipped fast, and seemed like a good deal with good style. I also purchased 2 of the optional lenses (clear and yellow). For my first ride with them, I switched out the lenses using the directions. They required an unreasonable amount of force to be placed on the nose piece to get the lens to seat in the upper recess. The nose piece looks like VERY flimsy plastic. On the second ride, I had to change the lenses again, but this time (again following the instructions) the nose piece snapped right off. I had to glue the nose piece back on to finish my ride. I tried to get a warranty, as I only got ONE ride with these glasses before they broke (following their instructions for lens change-out). They denied the warranty, because the glasses had been modified (glued back together). Mind you, they broke BEFORE the glue, and the company was informed that they were only glued to safely finish a long distance ride. It's not like they would be able to fix them if they weren't glued. They just wanted an excuse not to stand behind their product. So, BEWARE! Don't buy these thinking that you can change the lenses. And consider them disposable, because they don't stand behind their products.