It's an overhead rolling door. It's a security door that is used often in larger malls, liquor stores, jewelry shops, and so forth. It is pulled down from the top. Some are automatic. They allow consumers to see the merchandise inside while, at the same time, providing security during lockup. There are several styles of these types of security doors.

I think the generic term here is ‘security shutters’. You could also add the word ‘rolling’ or drop the word ‘security’.

steel net roller shutter