Inventories

3 Months Ended

Mar. 31, 2018

Inventories [Text Block]

4. Inventories

Inventories as of December 31, 2017 and March 31, 2018 consisted of the following:

		December 31,		March 31,
		2017		2018
Raw materials	$	1,814,704	$	2,547,462
Work in progress		2,188,193		2,453,321
Finished goods		5,829,508		6,604,625
	$	9,832,405	$	11,605,408

During the three months ended March 31, 2017 and 2018, write-downs of obsolete inventories to lower of cost or market of $150,156 and $1,199, respectively, were charged to cost of revenues.