其實有冇用?見佢寫dust mask, 但又係n95
Disposable Dust Mask, 7 Layer N95 Particulate Respirator Face Masks with Breathing Valve Filter Activated Carbon PM2.5 Anti Pollution Flu Mouth Mask, 25 pack
https://www.amazon.com/dp/B07TXCL4C8/ref=cm_sw_r_cp_api_i_HiEkEb3CDEW5N