A quality product for Polaroid, it's heavy solid, all-metal ... solid. It makes the job well is asked, it adapts well to the lens. Warning, this is however not a fish eye 400, so it's net correct way to the center and very blur on the sides. You also lose a lot in brightness, to see what happens in inner ....
In general, it was well worth the money and fish eyes being rather a gadget which is used sporadically in the photo, I think this is an excellent quality / price ratio, you will find no better, I searched a lot before taking it.