Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 1,565	$ 13,250
Marketable securities	15,664	3,803
Accounts receivable, net of allowances of $38 and $35, respectively	3,880	3,393
Inventories, net	4,302	3,875
Prepaid expenses and other current assets	168	229
Total Current Assets	25,579	24,550
Property, plant and equipment:
Land	536	536
Buildings and improvements	3,973	3,973
Machinery and equipment	17,176	16,974
Gross property, plant and equipment	21,685	21,483
Less: accumulated depreciation	(19,515)	(19,304)
Net property, plant, and equipment	2,170	2,179
Intangible assets, net	515	552
Deferred income taxes, net	155	173
Other assets, net		101
Total Assets	28,419	27,555
Current Liabilities:
Accounts payable	1,339	1,477
Accrued compensation and commissions	1,180	872
Other accrued expenses	300	278
Total Current Liabilities	2,819	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 June 30, 2018, and 4,774,477 shares issued and 4,692,893 shares outstanding at December 31, 2017	47	47
Additional paid-in capital	40,042	40,035
Accumulated deficit	(13,909)	(14,609)
Treasury stock, 81,584 shares held in treasury at cost at June 30, 2018 and December 31, 2017	(580)	(580)
Accumulated other comprehensive income		35
Total Stockholders' Equity	25,600	24,928
Total Liabilities and Stockholders' Equity	$ 28,419	$ 27,555