CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue
Product sales	$ 7,205,000	$ 6,485,000	$ 21,868,000	$ 20,036,000
Barrier rentals	1,708,000	3,171,000	8,667,000	4,820,000
Royalty income	676,000	484,000	1,788,000	1,165,000
Shipping and installation revenue	3,511,000	2,375,000	8,302,000	6,768,000
Total revenue	13,100,000	12,515,000	40,625,000	32,789,000
Cost of goods sold	9,898,000	8,674,000	28,388,000	24,971,000
Gross profit	3,202,000	3,841,000	12,237,000	7,818,000
Operating expenses
General and administrative expenses	1,215,000	1,271,000	3,880,000	3,553,000
Selling expenses	719,000	521,000	2,010,000	1,684,000
Total operating expenses	1,934,000	1,792,000	5,890,000	5,237,000
Operating income (loss)	1,268,000	2,049,000	6,347,000	2,581,000
Other income (expense)
Interest expense	(47,000)	(53,000)	(145,000)	(166,000)
Interest income	10,000	8,000	29,000	26,000
Gain (loss) on sale of assets	205,000	(8,000)	293,000	58,000
Gain on forgiveness of PPP loan	2,692,000	0	2,692,000	0
Other income	8,000	22,000	41,000	41,000
Total other income (expense)	2,868,000	(31,000)	2,910,000	(41,000)
Income (loss) before income tax expense (benefit)	4,136,000	2,018,000	9,257,000	2,540,000
Income tax expense (benefit)	442,000	469,000	1,711,000	588,000
Net income (loss)	$ 3,694,000	$ 1,549,000	$ 7,546,000	$ 1,952,000
Basic and diluted earnings (loss) per common share	$ 0.71	$ 0.30	$ 1.45	$ 0.38
Weighted average number of common shares outstanding:
Basic	5,202	5,184	5,202	5,184
Diluted	5,220	5,184	5,217	5,184