Recently, the press conference on COVID-19 prevention and control in Beijing suggested that key personnel in the takeout and distribution industry and ordinary citizens should wear N95 and kn95 masks in the case of sealing, controlling areas or visiting hospitals for medicine. The reporter found that the purchase channels of N95 and kn95 masks are smooth and the supply of goods is sufficient. Most of the delivery riders and citizens are also very cooperative and consciously wear such masks in relevant scenes to protect themselves. However, on some e-commerce platforms, there are a variety of mask advertisements. Consumers reflected to this newspaper: "they thought they bought a kn95 mask, and only found it after unpacking it. It was either loose and poorly wrapped, or it had a strange smell. Or it was just like kn95, but it was actually an ordinary mask. What if they bought it wrong and could not play a protective role?" This reporter interviewed experts in relevant fields to explain how to buy masks for you. The Beijing Municipal Bureau of Commerce recently issued a new version of the guidelines for the prevention and control of takeout delivery personnel during the COVID-19 epidemic, which stipulates that takeout delivery personnel must wear N95 or kn95 masks during the delivery process. Over the past few days, the reporter has conducted an investigation on the wearing of masks by the delivery personnel and found that the vast majority of delivery riders can conscientiously implement this requirement, whether they are delivering meals upstairs or flying on the delivery road, they wear such masks. A rider running orders on a delivery platform told the reporter that the company has issued clear regulations requiring riders to wear N95 or kn95 masks during work. When riders receive orders online every day, they must first upload a photo of wearing such masks. The system will conduct spot checks from time to time on the way of running orders. If the photo review does not meet the requirements, riders will be warned and restricted from receiving orders. The rider said: "after all, it's a special period. Doing so can better protect yourself. So many communities come and go in and out every day. Everyone is confident that the protection is in place." Another delivery rider told the reporter that there are many such masks now, and there are many on the Internet, and the price is affordable. "I bought a lot a while ago, but it's less than ten cents." When the reporter asked about the quality of the mask, he shook his head and said: "I feel that the quality is very general. The mask has a peculiar smell, and some of them do not even have a nose bridge, but I can't tell. It looks really like it. The merchants also publicize it this way, and it is very cheap. So I bought it to wear it." A resident living in the controlled area told the reporter that he was also worried about buying fake kn95 masks when he bought masks online. "The advertisement of the mask is full of hype, and some ordinary masks are made into three-dimensional ones, which look like kn95 masks. The merchants also publicize that they are epidemic prevention masks, medical kn95 protective masks, and bacterial filtering effect ≥ 99%. I was very excited and almost placed an order." He specially asked the customer service personnel whether the mask was kn95 mask, but the customer service personnel never replied. Then he carefully looked at the product details page and consulted his knowledgeable neighbors. Only then did he discover that the so-called medical kn95 mask mentioned by this online shop was actually a medical surgical mask. "Isn't this playing a word game and fooling consumers?" Investigation