Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
OPERATING ACTIVITIES
Net income	$ 169,000	$ 27,000
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation	148,000	115,000
Amortization of finite-lived intangible assets	18,000	19,000
Stock-based compensation	233,000	78,000
Loss on equity investment in unconsolidated subsidiary		76,000
Realized loss on sale of marketable securities	744,000
Unrealized gain on marketable securities	(789,000)	(127,000)
Deferred income tax expense	(165,000)	29,000
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable, net	(588,000)	209,000
Increase in inventories, net	(427,000)	(59,000)
Decrease (increase) in prepaid expenses and other assets	31,000	(156,000)
Increase in accounts payable, accrued compensation, income taxes and commissions and other	72,000	191,000
Net cash (used in) provided by operating activities	(554,000)	402,000
INVESTING ACTIVITIES
Capital expenditures	(207,000)	(55,000)
Proceeds from sale of marketable securities	397,000
Purchase of marketable securities	(7,000,000)
Net cash used in investing activities	(6,810,000)	(55,000)
(Decrease) increase in cash and cash equivalents	(7,364,000)	347,000
Cash and cash equivalents at beginning of period	29,016,000	18,331,000
Cash and cash equivalents at end of period	21,652,000	18,678,000
Supplemental Disclosure:
Income taxes paid	$ 50,000	27,000
Non-cash subscription agreement (Note C)		$ 2,725,000