ventilation block

perforated block, made of concrete or other material, used in permanent wall openings for ventilation and natural lighting of buildings

en-US/ˌvɛnəˈleɪʃən ˈblɑk/
en-GB/ˌvɛntɪˈleɪʃən ˈblɒk/

زمرے:

building materialconcrete block