CONDENSED BALANCE SHEETS (unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets
Cash and cash equivalents	$ 10,072	$ 9,870
Investments	56	56
Trade receivables, less allowance for credit losses of $11 and $11, respectively	1,119	1,283
Inventories	1,811	1,751
Other current assets	218	179
Total current assets	13,276	13,139
Deferred income tax asset, net	336	355
Property and equipment, net	927	951
Total assets	14,539	14,445
Current liabilities
Accounts payable	189	291
Accrued expenses	494	323
Accrued income tax	61	76
Total current liabilities	744	690
Commitments and contingencies
Stockholders' equity
Common stock par value $0.10 per share; authorized 10,000,000 shares; 3,428,021 shares issued and outstanding	342	342
Additional paid-in capital	2,259	2,230
Retained earnings	11,194	11,183
Total stockholders' equity	13,795	13,755
Total liabilities and stockholders' equity	$ 14,539	$ 14,445