“Chances are you are going to break these at some point, when taking them out of the sunglassframe.
It happend to me several times now when skiing so I figured it was the cold.
But it has happened now as well on a day in spring. So I guess it's the type of plastic that can only take some much bending before it snaps. Changing the optometric glasses in this frame is easy, so changing these when this frame brakes is no hassle. But you definitely what to keep a reserve pair, so you don't get stuck when it happens.
They are cheap and still easy to come by, so I hope the K3 frame will be here forever, and so will be the clip on.
I have a huge collection of K3 frames an lenses by now, so I hope Siroko will keep these items in their catalogue forever.”