Statements of Income (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Net sales	$ 2,838,225	$ 3,390,205	$ 5,319,352	$ 6,645,149
Costs and expenses:
Cost of sales	1,340,854	1,561,090	2,463,930	3,117,580
Operating expenses	694,050	602,777	1,326,785	1,171,642
Research and development expense	107,868	111,660	222,262	214,642
Total costs and expenses	2,142,772	2,275,527	4,012,977	4,503,864
Income from operations	695,453	1,114,678	1,306,375	2,141,285
Other income (expense):
Investment income	70,573	100,007	155,260	198,080
Net gain (loss) on marketable securities	24,576	(9,501)	36,926	31,995
Total other income	95,149	90,506	192,186	230,075
Income before provision for income taxes	790,602	1,205,184	1,498,561	2,371,360
Provision for income taxes	163,776	248,959	310,840	489,693
Net income	$ 626,826	$ 956,225	$ 1,187,721	$ 1,881,667
Earnings per common share (basic and diluted) (in dollars per share)	$ 0.14	$ 0.21	$ 0.26	$ 0.41
Weighted average shares (basic and diluted) (in shares)	4,594,319	4,594,319	4,594,319	4,594,319