Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 7,062	$ 8,785
Investments	2,041	45
Trade receivables, less allowance for doubtful accounts of $11	1,039	1,036
Inventories	1,659	1,695
Other current assets	196	159
Income tax receivable	23	0
Total current assets	12,020	11,720
Deferred income tax asset, net	227	203
Intangible assets, net	294	489
Property and equipment, net	1,010	1,063
Total assets	13,551	13,475
Current liabilities
Current maturities of financing lease	6	5
Accounts payable	181	129
Accrued expenses	573	431
Total current liabilities	760	565
Long-term liabilities
Financing lease, net of current maturities	14	19
Total long-term liabilities	14	19
Commitments and contingencies
Stockholders' equity
Common stock par value $0.10 per share; authorized 10,000,000 shares; 3,395,521 shares issued and outstanding	339	339
Additional paid-in capital	2,035	2,030
Retained earnings	10,403	10,522
Total stockholders' equity	12,777	12,891
Total liabilities and stockholders' equity	$ 13,551	$ 13,475