This is a 16mm wide-angle lens for smartphones made by Ulanzi. I used it only once. I really liked it, but shortly after I bought it, the smartphone I replaced it with had a wide-angle lens with almost the same focal length, so I haven't used it since and have been storing it. I bought it on Amazon for 6999 yen. This focal length lens is apparently no longer sold, but it's a different focal length from the following series, so please refer to it. https://www.amazon.co.jp/gp/product/B0D5HWX9MW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1