I need to use an external directional antenna to create a long-distance wireless link (not very long that I need to buy a costly CPE). So, I have decided to buy an 8dbi/12dbi directional antenna from Aliexpress, but I don’t know much about antenna design and the sellers often write wrong parameters to sell more. So, I am posting the details here if anyone with antenna knowledge can help.
The antenna link: https://www.aliexpress.com/item/32980013712.html
Inside, it is formed by two plates. The driven element is a 40x50mm plate. The reflector is larger, curved, and grounded. A black plastic is there between the plates. But there is a metal bolt in the center causing electrical contact between the plates. Here I have attached some photos which were posted by a buyer. Can you please tell me if this design is good and is the antenna a good choice? Thank you.