Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net income (loss)	$ 410	$ (124)
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization	295	360
Deferred income taxes	38	(43)
Stock-based compensation expense	5	6
Interest accrued on Treasury Bills	(2)	(4)
Other	(7)	4
Change in:
Trade receivables	(48)	79
Inventories	(91)	123
Other current assets	(18)	(11)
Accounts payable	152	68
Accrued expenses	12	(101)
Income taxes receivable	23	(26)
Net cash from operating activities	769	331
Cash flows from (used in) investing activities
Purchases of Treasury Bills	(11,999)	(13,745)
Proceeds from the maturity of Treasury Bills	17,000	5,750
Purchase of property and equipment	(141)	(25)
Net cash from (used in) investing activities	4,860	(8,020)
Cash flows used in financing activities
Payments on financing lease	(6)	(6)
Proceeds from Paycheck Protection Program	0	645
Repayment of Paycheck Protection Program loan	0	(645)
Net cash used in financing activities	(6)	(6)
Net increase (decrease) in cash and cash equivalents	5,623	(7,695)
Cash and cash equivalents, beginning	1,090	8,785
Cash and cash equivalents, ending	6,713	1,090
Supplemental cash flow information
Cash paid during the year for income taxes	15	20
Cash paid during the year for interest	$ 1	$ 3