XML 45 R33.htm IDEA: XBRL DOCUMENT v3.20.2
Inventories (Tables)
9 Months Ended
Sep. 30, 2020
Inventories [Abstract]  
Schedule of inventories
   December 31,   September 30, 
   2019   2020 
Raw materials  $482,836   $408,288 
Work in progress   1,254,490    931,717 
Finished goods   6,929,388    2,279,527 
   $8,666,714   $3,619,532