CONDENSED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 1,179,498	$ 967,943
Short-term investments	1,814,878	1,442,939
Trade receivables, less allowance of $42,000 in 2013 and $43,000 in 2012	1,899,714	2,060,312
Inventories	2,515,698	2,678,864
Prepaid expenses and other assets	135,768	124,983
Income taxes receivable	91,671
Deferred income taxes	142,000	142,000
Total current assets	7,779,227	7,417,041
PROPERTY, PLANT, AND EQUIPMENT, at cost:
Land and building	6,110,906	6,063,965
Machinery and equipment	3,690,574	3,219,598
Office equipment	742,951	700,062
Vehicles	237,488	237,488
Gross property, plant, and equipment, at cost	10,781,919	10,221,113
Less accumulated depreciation	5,171,831	4,759,235
Net property, plant, and equipment, at cost	5,610,088	5,461,878
INTANGIBLE ASSETS, less accumulated amortization of $521,727 in 2013 and $482,107 in 2012	335,046	305,357
Total assets	13,724,361	13,184,276
CURRENT LIABILITIES:
Accounts payable	660,054	593,922
Accrued compensation	333,289	265,822
Other accrued liabilities	97,359	81,635
Income taxes payable		82,152
Total current liabilities	1,090,702	1,023,531
DEFERRED INCOME TAXES	431,000	366,000
Total liabilities	1,521,702	1,389,531
STOCKHOLDERS' EQUITY:
Preferred stock, par value $.10 per share; authorized 250,000 shares; issued none
Common stock, par value $.10 per share; authorized 4,750,000 shares; issued and outstanding 2,008,836 shares in 2013 and 1,998,475 shares in 2012	200,884	199,848
Additional paid-in capital	2,555,861	2,470,507
Retained earnings	9,445,914	9,124,390
Total stockholders' equity	12,202,659	11,794,745
Total liabilities and stockholders' equity	$ 13,724,361	$ 13,184,276