Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statements Of Comprehensive Income [Abstract]
Net sales	$ 8,555	$ 9,029
Cost of goods sold	4,310	4,188
Gross profit	4,245	4,841
Operating expenses
Selling and marketing	1,332	1,516
General and administrative	1,968	2,526
Research and development	973	836
Total operating expenses	4,273	4,878
Operating loss	(28)	(37)
Non-operating income
Interest expense	(1)	(1)
Interest income	407	110
Total non-operating income, net	406	109
Income before income taxes	378	72
Income tax expense (benefit)	103	(28)
Net income	275	100
Other comprehensive income (loss)
Change in unrealized value of available-for-sale securities, net of income tax	(1)	1
Other comprehensive income (loss)	(1)	1
Net comprehensive income	$ 274	$ 101
Basic
Net income per share	$ 0.08	$ 0.03
Weighted average shares	3,428,021	3,401,137
Diluted
Net income per share	$ 0.08	$ 0.03
Weighted average shares	3,428,021	3,432,843