Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2011	Aug. 31, 2010
Net sales	$ 9,252,063	$ 10,581,783	$ 21,761,551	$ 22,909,802
Cost of goods sold	6,544,644	8,004,666	16,622,309	17,437,158
Gross profit	2,707,419	2,577,117	5,139,242	5,472,644
Expenses:
Engineering	91,840	102,042	330,482	309,342
Selling	447,103	549,959	1,320,115	1,476,102
General and administrative	730,569	654,234	2,161,519	2,081,037
Total expenses	1,269,512	1,306,235	3,812,116	3,866,481
Income from operations	1,437,907	1,270,882	1,327,126	1,606,163
Other income (expense):
Interest expense	(120,202)	(121,085)	(321,910)	(310,879)
Other	46,523	16,908	77,821	68,869
Total other income (loss)	(73,679)	(104,177)	(244,089)	(242,010)
Income before income taxes	1,364,228	1,166,705	1,083,037	1,364,153
Income tax expense	344,392	414,903	257,035	477,446
Net income	$ 1,019,836	$ 751,802	$ 826,002	$ 886,707
Net income per share:
Basic (in Dollars per share)	$ 0.25	$ 0.19	$ 0.21	$ 0.22
Diluted (in Dollars per share)	$ 0.25	$ 0.19	$ 0.20	$ 0.22