Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating activities:
Net income	$ 1,845,000	$ 3,208,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	167,000	135,000
Provision for inventory reserves	74,000	180,000
Reversal of inventory reserves	(2,000)	(3,000)
Provision for sales returns and doubtful accounts	0	0
Stock based compensation	13,000	23,000
Deferred income taxes	4,000	(2,047,000)
Changes in values of marketable securities	(800,000)	498,000
Changes in assets and liabilities:
Accounts receivable	591,000	217,000
Inventories	1,231,000	1,184,000
Prepaid expenses and other current assets	(135,000)	25,000
Accounts payable	(17,000)	(1,602,000)
Accrued liabilities	179,000	(134,000)
Other assets and liabilities	0	7,000
Total adjustments	1,305,000	(1,517,000)
Net cash provided by operating activities	3,150,000	1,691,000
Investing activities:
Acquisition of property and equipment	(215,000)	(2,000)
Purchase of marketable securities	(7,835,000)	(1,234,000)
Sales of marketable securities	7,039,000	268,000
Net cash used for investing activities	(1,011,000)	(968,000)
Financing activities:
Dividend payments	(1,202,000)	(1,703,000)
Proceeds from stock options exercised	54,000	208,000
Net cash used for financing activities	(1,148,000)	(1,495,000)
Impact of exchange rates on cash	(3,000)	15,000
Net increase(decrease) in cash and cash equivalents	988,000	(757,000)
Cash and cash equivalents, beginning of period	5,217,000	5,974,000
Cash and cash equivalents, end of period	6,205,000	5,217,000
Cash paid for interest	0	0
Cash paid for income taxes, net	$ 559,000	$ 706,000