Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		6 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Net sales	$ 9,250,308	$ 11,685,169	$ 17,665,413	$ 17,997,383
Cost of goods sold	6,685,890	8,527,545	12,731,827	13,363,538
Gross profit	2,564,418	3,157,624	4,933,586	4,633,845
Expenses:
Engineering	101,125	73,351	203,692	158,411
Selling	483,782	424,528	973,519	791,312
General and administrative	1,180,552	1,165,979	2,244,662	1,828,101
Total expenses	1,765,459	1,663,858	3,421,873	2,777,824
Income from operations	798,959	1,493,766	1,511,713	1,856,021
Other income (expense):
Interest expense	(79,739)	(109,026)	(169,202)	(202,069)
Other	(9,443)	19,738	628,699	39,604
Total other income (loss)	(89,182)	(89,288)	459,497	(162,465)
Income before income taxes	709,777	1,404,478	1,971,210	1,693,556
Current tax expense	292,684	450,049	734,857	507,125
Deferred tax expense (benefit)	(97,147)	18,448	(97,147)	56,952
Net income	$ 514,240	$ 935,981	$ 1,333,500	$ 1,129,479
Net income per share:
Basic net income per share (in Dollars per share)	$ 0.13	$ 0.23	$ 0.33	$ 0.28
Diluted net income per share (in Dollars per share)	$ 0.13	$ 0.23	$ 0.33	$ 0.28
Weighted average outstanding shares used to compute basic net income per share (in Shares)	4,037,552	4,031,439	4,036,302	4,029,825
Weighted average outstanding shares used to compute diluted net income per share (in Shares)	4,051,692	4,047,787	4,049,480	4,047,346