Heading away from the deadly smog of Beijing for a few months' work may sound like the ideal tonic for tired lungs, but people still misses home.
British entrepreneur Dominic Johnson-Hill, who sees the opportunity and is selling hundreds of cans of Beijing Air for 3 pounds a go.
Johnson-Hill's ring-pull cans are decorated by city scenes, the warning "choking hazard" and the admission that they are actually made in Shenzhen.
More than 100 cans of the bizarre souvenir are sold daily on the shopping site Taobao.
"When I really miss Beijing I will open a can and sniff it," Mr Zhang, 26, said. "I love this city and the air quality is getting better."