Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (441,303)	$ (122,267)
Adjustments to reconcile net loss to net cash (used for) provided by operating activities:
Depreciation	614,695	555,124
Amortization of intangible assets	4,776	4,776
Amortization and write-off of debt issuance costs	1,960	97,948
Deferred income taxes		(14,632)
Stock-based compensation	34,629	77,404
(Gain) loss on disposal of fixed assets	(10,000)	3,266
Non-cash rent expense	2,679	1,490
Changes in:
Trade accounts receivable	(593,404)	(238,618)
Accrued interest income	495	21,932
Inventory	(29,936)	920,298
Prepaid expenses and other current assets	(169,271)	(215,513)
Other assets	2,787	4,739
Accounts payable and accrued expenses	(41,653)	(238,494)
Net cash (used for) provided by operating activities	(623,546)	857,453
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(349,316)	(1,252,147)
Maturities of investments	996,000	1,965,000
Proceeds from sale of fixed assets	10,000	600
Net cash provided by investing activities	656,684	713,453
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from debt issuance		8,600,000
Debt principal repayments	(190,377)	(8,519,078)
Payments of debt issuance costs	2,272	(39,789)
Proceeds from exercise of stock options	11,680
Net cash (used for) provided by financing activities	(176,425)	41,133
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(143,287)	1,612,039
BEGINNING CASH AND CASH EQUIVALENTS	6,949,937	6,293,293
ENDING CASH AND CASH EQUIVALENTS	6,806,650	7,905,332
CASH PAID FOR:
Interest expense	78,766	256,420
NON-CASH ACTIVITIES:
Change in capital expenditures included in accounts payable and accrued expenses	80,213	384,631
Net change in fair value of interest rate swaps, net of taxes		(43,895)
Operating lease right-of-use asset and operating lease liability		$ 1,313,698