See and Buy this product on Amazon.com store (affiliate):
The Laowa lenses as a range are certainly very interesting, sometimes unique and always deliver the goods in terms of performance. Traditional metal construction does mean a higher price, but we have to choose whether the trade-off of quality of results balances out the cost/performance equation. This will obviously be different for different users.
What we get is the widest lens in its class, with a fast, bright f/2.8 aperture, that performs very well indeed.
I really liked being able to capture such a wide field of view with such a tiny lens. The resolution is already quite good in most parts of the frame at f/2.8 and stopped down to f/8.0 it is offers a very even across frame performance. [...] The biggest downside of this lens is probably the flare resistance. [...] Nevertheless this lens can be a nice addition to many APS-C kits.
Lens Venus Optics Laowa 9mm f/2.8 Zero-D (for Sony E)