With a red coat, red cap and red armband, 62-year-old Gao Tianrui roams around the Shichahai area doing public service as a volunteer. Although he is from the US, he is practically indistinguishable from his local Beijing buddies.

Though he’d lived in Beijing for 23 years, Gao gained fame online last year after creating a video applying to become a "Xicheng Dama", a group of volunteers in their 50s and 60s who roam Xicheng district in central Beijing acting as public security volunteers.

Now Gao is one of the 70,000 "Xicheng Dama" in charge of the Lotus Market volunteer box. Staying near many tourist attractions in the Shichahai area, Gao answers questions from domestic and overseas tourists nearly every day.

Fluent in Chinese, Cantonese and English, Gao also helps translate useful information posted in the volunteer box.