At a higher price the thing would have fallen after "Hong Kong". Does not fit the Hubsan as indicated. Optics, yes, fisheye effect. But even if I stick the lens on my smartphone, I see the green edge of the image. The lens can be glued to a smartphone via Gelklebeposter example and simply removed again. Since the Hubsan but does not smooth contour to the camera, you can not even fix approach, the lens. Pity!