4. Inventories (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Inventories Details
Materials	$ 440,723	$ 720,113
Finished goods (including $489,400 and $304,500 held by customers at December 31, 2012 and 2013, respectively)	1,273,358	1,910,273
Total inventories	$ 1,714,081	$ 2,630,386