CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statements of Comprehensive Income (Loss) [Abstract]
Net sales	$ 2,137	$ 2,564	$ 4,182	$ 4,699
Cost of goods sold	1,069	1,156	2,092	2,125
Gross profit	1,068	1,408	2,090	2,574
Operating expenses
Selling and marketing	344	427	714	873
General and administrative	442	1,125	964	1,628
Research and development	238	221	506	452
Total operating expenses	1,024	1,773	2,184	2,953
Operating Income (loss)	44	(365)	(94)	(379)
Non-operating income
Interest expense	(1)	0	(1)	0
Interest income	95	7	188	8
Total non-operating income, net	94	7	187	8
Income (loss) before income tax expense (benefit)	138	(358)	93	(371)
Income tax expense (benefit)	22	(74)	21	(78)
Net income (loss)	116	(284)	72	(293)
Other comprehensive income (loss)
Change in unrealized value of available-for-sale securities, net of income tax	2	2	(2)	2
Other comprehensive income (loss)	2	2	(2)	2
Net comprehensive income (loss)	$ 118	$ (282)	$ 70	$ (291)
Basic
Net income (loss) per share	$ 0.03	$ (0.08)	$ 0.02	$ (0.09)
Weighted average shares	3,428,021	3,395,521	3,428,021	3,395,521
Diluted
Net income (loss) per share	$ 0.03	$ (0.08)	$ 0.02	$ (0.09)
Weighted average shares	3,443,394	3,395,521	3,443,930	3,395,521