This filter is very interesting. As stated in the product description, it mimics the flare of an anamorphic lens. However, this effect comes with some caveats.

First, this filter creates this effect using small lines of a blue diffusion-like material. That gives you an anamorphic look, but it tends to overdo it. Flares are much more solid than a true aspheric lens and become unusable in locations with many large light sources. However, this is better than buying a $2000 Sirui lens unless you have two grand sitting around.

Second, since the filter uses physical material to create the effect, it's easily visible when you're looking for it, otherwise it disappears in the image. In my experience, this side effect worsens with longer focal lengths.

Third, because the filter uses a physical material to mimic an anamorphic lens, autofocus sometimes gets muddled. I used this filter on my Sony A7IV with a Sigma 24-70mm 2.8 lens. At around 24mm, the autofocus would occasionally go haywire. Again, longer focal lengths exacerbate this problem, especially when focusing on subjects closer to the lens.

Pros: This filter is very cool despite the caveats I discussed. I used it in a short film and I loved it. is it perfect No, but nothing ever is. If you are looking to buy this filter I would recommend it. However, if you have a few thousand dollars burning a hole in your pocket, buy a true anamorphic lens like a Sirui 100mm. Overall a great purchase I have no regrets but be aware of the issues involved. If you want to use a fisheye lens: maybe not for you. If you want to get very close to a topic: Not for you. If you want to shoot in dynamic lighting with a longer focal length: this is for you.