Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 1,483	$ 13,250
Marketable securities	15,590	3,803
Accounts receivable, net of allowances of $36 and $35, respectively	3,652	3,393
Inventories, net	4,008	3,875
Prepaid expenses and other current assets	262	229
Total Current Assets	24,995	24,550
Property, plant and equipment:
Land	536	536
Buildings and improvements	3,973	3,973
Machinery and equipment	17,146	16,974
Gross property, plant and equipment	21,655	21,483
Less: accumulated depreciation	(19,408)	(19,304)
Net property, plant, and equipment	2,247	2,179
Intangible assets, net	532	552
Deferred income taxes, net	180	173
Other assets, net	2	101
Total Assets	27,956	27,555
Current Liabilities:
Accounts payable	1,499	1,477
Accrued compensation and commissions	1,052	872
Other accrued expenses	255	278
Total Current Liabilities	2,806	2,627
Commitments and Contingencies (Note L)
Stockholders’ Equity
Common stock, $0.01 par value - 10,000,000 shares authorized; 4,779,977 shares issued and 4,698,393 shares outstanding at March 31, 2018, and 4,774,477 shares issued and 4,692,893 shares outstanding at December 31, 2017	47	47
Additional paid-in capital	40,064	40,035
Accumulated deficit	(14,381)	(14,609)
Treasury stock, 81,584 shares held in treasury at cost at March 31, 2018 and December 31, 2017	(580)	(580)
Accumulated other comprehensive income		35
Total Stockholders' Equity	25,150	24,928
Total Liabilities and Stockholders' Equity	$ 27,956	$ 27,555