CONDENSED BALANCE SHEETS (USD $)	Mar. 31, 2014	Dec. 31, 2013
CURRENT ASSETS:
Cash and cash equivalents	$ 2,143,245	$ 1,704,300
Short-term investments	1,260,071	1,464,878
Trade receivables, less allowance of $46,000 in 2014 and $62,000 in 2013	2,213,073	2,050,853
Inventories	2,888,597	2,554,942
Prepaid expenses and other assets	162,391	103,687
Income taxes receivable		16,400
Deferred income taxes	150,000	150,000
Total current assets	8,817,377	8,045,060
PROPERTY, PLANT, AND EQUIPMENT, at cost:
Land and building	6,123,890	6,123,890
Machinery and equipment	3,877,477	3,781,282
Office equipment	725,229	722,567
Vehicles	237,341	237,194
Gross property, plant, and equipment, at cost	10,963,937	10,864,933
Less accumulated depreciation	5,372,156	5,230,837
Net property, plant, and equipment, at cost	5,591,781	5,634,096
INTANGIBLE ASSETS, less accumulated amortization of $179,586 in 2014 and $173,143 in 2013	332,852	322,647
Total assets	14,742,010	14,001,803
CURRENT LIABILITIES:
Accounts payable	878,692	532,294
Accrued compensation	327,943	274,936
Other accrued liabilities	102,099	67,755
Income taxes payable	77,601
Total current liabilities	1,386,335	874,985
DEFERRED INCOME TAXES	527,000	527,000
Total liabilities	1,913,335	1,401,985
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 2,014,253 shares in 2014 and 2,012,170 shares in 2013	201,425	201,217
Additional paid-in capital	2,615,772	2,592,038
Retained earnings	10,011,478	9,806,563
Total stockholders' equity	12,828,675	12,599,818
Total liabilities and stockholders' equity	$ 14,742,010	$ 14,001,803