Restricted cash, non-current

9 Months Ended

Sep. 30, 2019

Restricted Net Assets [Abstract]

Restricted cash, non-current

4. Restricted cash, non-current

The Group's restricted cash balance of $510,218 as of September 30, 2019 was long-term bank deposits held as collateral for issuance of letters of credit. These deposits will be released when the related letters of credit are settled by the Group.