CONDENSED BALANCE SHEETS - USD ($)	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 1,162,188	$ 929,700
Short-term investments	2,675,000	2,895,000
Trade receivables, less allowances of $75,000 as of March 31, 2018 and $53,000 as of December 31, 2017	2,031,907	2,190,260
Inventories	2,368,831	2,086,065
Prepaid expenses and other assets	193,828	168,242
Income taxes receivable	42,738	2,116
Total current assets	8,474,492	8,271,383
PROPERTY, PLANT, AND EQUIPMENT, at cost:
Land and building	9,218,220	9,207,790
Machinery and equipment	5,001,384	4,968,595
Office equipment	1,578,976	1,573,191
Vehicles	245,679	245,679
Gross property, plant, and equipment, at cost	16,044,259	15,995,255
Less accumulated depreciation	(7,893,500)	(7,693,594)
Total property, plant, and equipment, at cost	8,150,759	8,301,661
INTANGIBLE ASSETS, less accumulated amortization of $181,470 as of March 31, 2018 and $174,991 as of December 31, 2017	360,278	351,186
Total assets	16,985,529	16,924,230
CURRENT LIABILITIES:
Current portion of long-term debt, net	131,797	130,899
Accounts payable	608,689	321,860
Accrued compensation	232,690	360,554
Other accrued liabilities	112,478	62,468
Total current liabilities	1,085,654	875,781
LONG-TERM LIABILITIES
Long-term debt, less current portion, net	2,912,950	2,946,518
Deferred income taxes	156,839	144,000
Total long-term liabilities	3,069,789	3,090,518
Total liabilities	4,155,443	3,966,299
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Preferred stock, par value $.10 per share; authorized 250,000 shares: none issued
Common stock, par value $.10 per share; authorized 4,750,000 shares; issued and outstanding 1,983,553 shares as of March 31, 2018 and December 31, 2017	198,355	198,355
Additional paid-in capital	2,712,283	2,709,390
Retained earnings	9,919,448	10,050,186
Total stockholders' equity	12,830,086	12,957,931
Total liabilities and stockholders' equity	$ 16,985,529	$ 16,924,230